Document And Entity Information
Note To Financial Statement Details Textual
Interest expense
us-gaap_InterestExpense
Total interest expense
Interest expense
statementsignificantaccountingpoliciespolicies
statementnote1summaryofsignificantaccountingpoliciestables
statementnote2businesscombinationstables
Investment securities available-for-sale
Available-for-sale Securities
statementnote3investmentsecuritiestables
statementnote4loanstables
statementnote5premisesandequipmenttables
Segment Reporting Disclosure [Text Block]
statementnote6depositstables
statementnote7federalhomeloanbankadvancesandborrowingstables
statementnote8incometaxestables
Interest on borrowings
statementnote9commitmentsandcontingenciestables
statementnote10derivativefinancialinstrumentsandhedgingtransactionstables
statementnote11employeebenefitplanstables
statementnote12relatedpartytransactionstables
statementnote14regulatorymatterstables
statementnote15fairvaluemeasurementsanddisclosurestables
statementnote16nationalcommercecorporationparentcompanyonlyfinancialinformationtables
statementnote17segmentreportingtables
Interest on subordinated debt
statementnote18goodwillandintangibleassetstables
statementnote20subsequenteventstables
statementselectedquarterlyfinancialdataunauditedtables
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive
Thereafter
statementnote1summaryofsignificantaccountingpoliciespremisesandequipmentestimatedusefullivesdetails
statementnote1summaryofsignificantaccountingpoliciesreconciliationofcomponentsofbasicanddilutedearningspersharedetails
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour
2020
statementnote2businesscombinationssummaryofestimatedfairvalueofassetsandliabilitiesacquireddetails
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive
2021
statementnote2businesscombinationssupplementalproformainformationdetails
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo
2018
statementnote2businesscombinationssummaryofloansatacquisitiondatedetails
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree
2019
statementnote2businesscombinationssummaryofpurchasedcreditimpairedloansatacquisitiondetails
statementnote2businesscombinationssummaryofchangesincarryingamountofaccretableyieldonacquiredloansdetails
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths
2017
statementnote3investmentsecuritiesamorizedcostandfairvalueofheldtomaturitydebtsecuritiesdetails
us-gaap_TimeDepositMaturitiesYearFive
2021
statementnote3investmentsecuritiesamortizedcostandfairvalueofavailableforsaledebtsecuritiesdetails
statementnote3investmentsecuritiesdebtsecuritieswithunrealizedlossesdetails
us-gaap_TimeDepositMaturitiesYearThree
2019
statementnote3investmentsecuritiesamortizedcostandestimatedfairvalueofsecuritiesdetails
us-gaap_TimeDepositMaturitiesYearFour
2020
statementnote4loanssummaryofmajorclassificationofloansdetails
statementnote4loanssummaryofallowanceforloanlossesandrecordedinvestmentinloansbyportfoliosegmentdetails
us-gaap_TimeDepositMaturitiesYearTwo
2018
Interest on deposits
statementnote4loanssummaryofimpairedloansbyclassofloansdetails
Other investments
Other investments
statementnote4loanssummaryofagingofrecordedinvestmentinpastdueandnonaccrualloandetails
us-gaap_TimeDepositMaturitiesYearOne
2017
statementnote4loanssummaryofriskcategoryofloansbyclassofloansdetails
statementnote5premisesandequipmentmajorclassificationsofpremisesandequipmentdetails
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
statementnote6depositscontractualmaturitiesoftimedepositsdetails
statementnote7federalhomeloanbankadvancesandborrowingsadvancesoutstandingdetails
statementnote8incometaxescomponentsofincometaxexpensedetails
statementnote8incometaxesincometaxreconcilliationdetails
statementnote8incometaxesdeferredtaxesdetails
us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Investment in sudsidiaries
statementnote9commitmentsandcontingenciesfinancialinstrumentswithcreditriskdetails
OAEM [Member]
A category of financing OAEM receivables.
statementnote9commitmentsandcontingenciesfutureminimumrentonoperatingleasesdetails
statementnote10derivativefinancialinstrumentsandhedgingtransactionsderivativeinstrumentsdetails
statementnote10derivativefinancialinstrumentsandhedgingtransactionsderivativeinstrumentsdetails C2 E92 F E193 A14 A A D97 B4 E F775 F A A59 A0
us-gaap_FiniteLivedIntangibleAssetUsefulLife
Finite-Lived Intangible Asset, Useful Life
statementnote11employeebenefitplansstockoptionactivitydetails
statementnote12relatedpartytransactionsactivityforrelatedpartyloansdetails
statementnote14regulatorymatterscapitalamountsandratiosdetails
statementnote15fairvaluemeasurementsanddisclosuresassetsandliabilitiesmeasuredatfairvalueonarecurringbasisdetails
statementnote15fairvaluemeasurementsanddisclosuresassetsmeasuredatfairvalueonanonrecurringbasisdetails
Interest expense:
statementnote15fairvaluemeasurementsanddisclosuressignificantunobservableinputsdetails
statementnote15fairvaluemeasurementsanddisclosurescarryingamountsandestimatedfairvaluesofthecompanysfinancialinstrumentsdetails
statementnote16nationalcommercecorporationparentcompanyonlyfinancialinformationbalancesheetsdetails
statementnote16nationalcommercecorporationparentcompanyonlyfinancialinformationstatementsofearningsdetails
statementnote16nationalcommercecorporationparentcompanyonlyfinancialinformationstatementsofcashflowsdetails
Interest income
us-gaap_InterestAndDividendIncomeOperating
Total interest income
Interest income
statementnote17segmentreportingreconciliationofreportablesegmentrevenueexpensesandprofitdetails
statementnote18goodwillandintangibleassetschangesincarryingamountofgoodwilldetails
statementnote18goodwillandintangibleassetscoredepositintangibleassetsdetails
statementnote18goodwillandintangibleassetsestimatedamortizationexpensedetails
statementnote20subsequenteventssummaryofestimatedfairvalueofassetsandliabilitiesacquireddetails
statementselectedquarterlyfinancialdataunauditedselectedquarterlyfinancialdatadetails
Notes To Financial Statements
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Notes To Financial Statements [Abstract]
us-gaap_InterestBearingDomesticDepositCertificatesOfDeposits
Interest-bearing Domestic Deposit, Certificates of Deposits
us-gaap_CashAndCashEquivalentsAtCarryingValue
Cash and cash equivalents
Cash and cash equivalents
Cash and cash equivalents at beginning of the period
Cash and cash equivalents at end of the period
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]
Interest-bearing deposits with banks
Interest on interest-bearing deposits and federal funds sold
Cash and due from banks
Cash and due from banks
Interest and dividends on taxable investment securities
us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit
Time Deposits, at or Above FDIC Insurance Limit
Interest on non-taxable investment securities
Deposit Liabilities Disclosures [Text Block]
us-gaap_DeferredTaxAssetsNet
Net deferred income tax assets
Interest and fees on loans
us-gaap_DeferredTaxAssetsGross
Total gross deferred income tax assets
us-gaap_DeferredTaxAssetsOther
Other
us-gaap_DeferredTaxAssetsGoodwillAndIntangibleAssets
Goodwill and intangible assets
us-gaap_NotesReceivableNet
Acquired loans with deteriorated credit quality
Accrued interest receivable
us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment
Premises and equipment
Interest and dividend income:
us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
Accrued expenses
Mortgage origination and fee income
us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses
Allowance for loan losses
Service charges and fees on deposit accounts
us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
Stock-based compensation
Deferred compensation
Bank-owned life insurance
Bank-owned life insurance
us-gaap_FinancingReceivableAllowanceForCreditLosses
Less: allowance for loan losses
Allowance for loan losses
Balance
Balance
us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Operating loss carryforwards and credits
Business Combinations Policy [Policy Text Block]
Other real estate
Deferred income tax assets:
Earnings Per Share, Policy [Policy Text Block]
IPO [Member]
us-gaap_LoansAndLeasesReceivableNetReportedAmount
Loans, net
Total net loans
Income Tax, Policy [Policy Text Block]
Sale of Stock [Axis]
Sale of Stock [Domain]
us-gaap_DeferredTaxLiabilities
Total gross deferred income tax liabilities
Less: Unearned fees
Loans, net of unearned income
us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets
Core deposit intangible
Loans and leases
Loans
us-gaap_DeferredTaxLiabilitiesInvestments
Investment in pass-through entity
Derivatives
us-gaap_DeferredTaxLiabilitiesUnrealizedGainsOnTradingSecurities
Unrealized gains on investment securities available-for-sale
Compensation Related Costs, Policy [Policy Text Block]
us-gaap_DeferredTaxLiabilitiesPrepaidExpenses
Prepaid expenses
Deferred income tax liabilities:
us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
Change in valuation allowance
us-gaap_CurrentIncomeTaxExpenseBenefit
Current
Other noninterest income
us-gaap_NoninterestIncomeOther
Total other income
Noninterest income
Asset Class [Domain]
Income from bank-owned life insurance
Income from bank-owned life insurance
Asset Class [Axis]
us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss
Net interest income after provision for loan losses
Other income:
Provision for loan losses
Provision for loan losses
Provision for loan and lease losses
Provisions charged to operating expense
Wealth management fees
Merchant sponsorship revenue
Net interest income
us-gaap_InterestIncomeExpenseNet
Net interest income
Net interest income
us-gaap_OtherIncome
Other
Amendment Flag
Goodwill and Intangible Assets, Policy [Policy Text Block]
State and Local Jurisdiction [Member]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]
Income Tax Authority [Domain]
Current Fiscal Year End Date
Domestic Tax Authority [Member]
ncom_ResidentialMortgageLoansInterestRateCommitmentsExpirationPeriod
Residential Mortgage Loans Interest Rate Commitments Expiration Period
Residential mortgage loans interest rate commitments expiration period.
Income Tax Authority [Axis]
Statement of Financial Position [Abstract]
Document Fiscal Period Focus
ncom_MortgageBankingDerivativesInterestRateLockCommitments
Mortgage Banking Derivatives Interest Rate Lock Commitments
Mortgage banking derivatives interest rate lock commitments.
Document Fiscal Year Focus
Document Period End Date
Document Type
Statement of Cash Flows [Abstract]
Statement of Stockholders' Equity [Abstract]
Document Information [Line Items]
Document Information [Table]
Entity Public Float
Entity Filer Category
Property, Plant and Equipment, Useful Life (Year)
Entity Current Reporting Status
Entity Voluntary Filers
Entity Well-known Seasoned Issuer
Construction in Progress [Member]
Furniture and Fixtures [Member]
Building and Building Improvements [Member]
Entity Central Index Key
Entity Registrant Name
Entity [Domain]
Business Acquisition, Acquiree [Domain]
Legal Entity [Axis]
Leasehold Improvements [Member]
Business Acquisition [Axis]
Land [Member]
Property, Plant and Equipment, Type [Axis]
Property Plant and Equipment Useful Life [Table Text Block]
Property Plant And Equipment Useful Life Table
Property, Plant and Equipment, Type [Domain]
Property, Plant and Equipment, Policy [Policy Text Block]
Directors' Shares [Member]
Refers to information regarding directors' shares.
Entity Common Stock, Shares Outstanding (in shares)
Transfers and Servicing of Financial Assets, Policy [Policy Text Block]
us-gaap_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssigned
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned
Shares of common stock issued (in shares)
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares
us-gaap_OperatingLossCarryforwards
Operating Loss Carryforwards
Trading Symbol
Assets
Net change in cash
Net change in cash and cash equivalents
Marketable Securities, Policy [Policy Text Block]
us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value
us-gaap_ImpairedFinancingReceivableRelatedAllowance
Related allowance
Net cash provided by financing activities
Net cash provided by financing activities
Net cash used by operating activities
Net cash provided by operating activities
Net cash used by investing activites
us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
Net cash used by investing activities
us-gaap_ImpairedFinancingReceivableRecordedInvestment
Recorded investment
us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Recorded investment without related allowance
us-gaap_PaymentOfFinancingAndStockIssuanceCosts
Stock offering expenses related to acquisition
us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Recorded investment with related allowance
us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Average recorded investment
Tax benefit resulting from exercise of stock options
us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
Average recorded investment without related allowance
us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
Average recorded investment with related allowance
us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Unpaid principal balance
us-gaap_PaymentsOfStockIssuanceCosts
Stock offering expenses
us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
Unpaid principal balance without related allowance
us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Unpaid principal balance with related allowance
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
Net identifiable assets acquired over liabilities assumed
us-gaap_PaymentsOfDividendsMinorityInterest
Cash distribution paid to noncontrolling interests
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
Net assets acquired over liabilities assumed
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Total liabilities
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFinancialLiabilities
Total deposits
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther
Other liabilities
Other
Change in valuation allowance
us-gaap_PaymentsForRepurchaseOfCommonStock
Stock repurchase
Proceeds from exercise of options and warrants
us-gaap_IncomeTaxReconciliationMinorityInterestIncomeExpense
Noncontrolling interest
us-gaap_IncomeTaxReconciliationTaxExemptIncome
Tax-exempt interest
Proceeds from exercise of stock options and warrants
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
Total assets
Proceeds from stock offering
Class of Financing Receivable, Type [Domain]
Construction Loans [Member]
us-gaap_ProceedsFromIssuanceOfCommonStock
Proceeds from Issuance of Common Stock
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Premises and equipment, net
Class of Financing Receivable, Type [Axis]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets
Other assets
Unallocated Financing Receivables [Member]
Consumer Portfolio Segment [Member]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
Other real estate and repossessions
Financing Receivable Portfolio Segment [Domain]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill
us-gaap_NoninterestExpense
Total other expense
Noninterest expense
Financing Receivable Portfolio Segment [Axis]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables
Net loans
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsMarketableSecurities
Investment securities
Loans and Leases Receivable, Origination Fees, Discounts or Premiums, and Direct Costs to Acquire Loans Policy [Policy Text Block]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
Cash and cash equivalents
Other expense:
Fair value of total consideration transferred
Business Combination, Consideration Transferred
Fair value of Company stock issued
Value of assumed stock options
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]
ncom_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsAllowanceForLoanLosses
Allowance for loan losses
Business combination recognized identifiable assets acquired and liabilities assumed current assets allowance for loan losses.
ncom_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBankOwnedLifeInsurance
Bank-owned life insurance
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Bank Owned Life Insurance
Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block]
ncom_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsLoans
Loans
Business combination recognized identifiable assets acquired and liabilities assumed current assets loans.
Non-interest bearing deposits
Business combination recognized identifiable assets acquired and liabilities assumed non interest bearing deposits.
us-gaap_BusinessAcquisitionSharePrice
Business Acquisition, Share Price
us-gaap_PaymentsOfDebtIssuanceCosts
Payments of Debt Issuance Costs
Debt offering expenses
Pre-tax income at statutory rate
us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Business Acquisition, Percentage of Voting Interests Acquired
State income tax expense, net
Interest-bearing deposits
Business combination recognized identifiable assets acquired and liabilities assumed interest bearing deposits.
Cash and Cash Equivalents, Policy [Policy Text Block]
Basis of Accounting, Policy [Policy Text Block]
Income Tax Disclosure [Text Block]
Accounting Policies [Abstract]
Income before income taxes
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Earnings before income taxes
us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted
Diluted earnings per common share (in dollars per share)
us-gaap_DerivativeNetHedgeIneffectivenessGainLoss
Derivative, Net Hedge Ineffectiveness Gain (Loss)
us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings
Repayment of Federal Home Loan Bank advances
us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Net earnings
Business Acquisition, Pro Forma Information [Table Text Block]
us-gaap_BusinessAcquisitionsProFormaRevenue
Net interest income
Credit Facility [Domain]
Pass [Member]
Credit Facility [Axis]
Internal Credit Assessment [Axis]
Internal Credit Assessment [Domain]
us-gaap_PartnersCapitalAccountUnitsSoldInPrivatePlacement
Partners' Capital Account, Units, Sold in Private Placement
us-gaap_PartnersCapitalAccountPrivatePlacementOfUnits
Partners' Capital Account, Private Placement of Units
Issuance of subordinated debt
Proceeds from Issuance of Subordinated Long-term Debt
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Measured by Acquired Company [Member]
Refers to information regarding the measuring of information by an acquired company.
Fair Value Adjustments [Member]
Refers to information regarding fair value adjustments.
Substandard [Member]
Doubtful [Member]
Schedule of Goodwill [Table Text Block]
Goodwill and Intangible Assets Disclosure [Text Block]
us-gaap_RepaymentsOfShortTermDebt
Repayment of short-term debt
us-gaap_RelatedPartyDepositLiabilities
Related Party Deposit Liabilities
us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Diluted common shares (in shares)
Core Deposits [Member]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Diluted net earnings per share (in dollars per share)
Diluted earnings per common share (in dollars per share)
Estimated value per share of the Company's stock (in dollars per share)
Consideration for the estimated value, per share of the companys' stock in regards to the business acquisition.
Weighted average common shares outstanding (in shares)
Equity Interest Issued or Issuable, Type [Domain]
Equity Interest Type [Axis]
Net earnings per share (in dollars per share)
Basic earnings per common share (in dollars per share)
us-gaap_FinancingReceivableModificationsNumberOfContracts2
Financing Receivable, Modifications, Number of Contracts
Related Party Transactions Disclosure [Text Block]
Schedule of Related Party Transactions [Table Text Block]
United Group Banking Company of Florida, Inc. [Member]
Refers to information regarding the United Group Banking Company of Florida, Inc.
Schedule Of Loans Acquired [Table Text Block]
The tabular disclosure of loans acquired.
ncom_BusinessAcquisitionImpairedLoans
Acquired Impaired Loans
Impaired loans acquired during the acquisition.
Net change in deposits
Impaired Financing Receivables [Table Text Block]
ncom_BusinessAcquisitionPerformingLoans
Acquired Performing Loans
Performing loans acquired during the acquisition.
Accretable discount
Certain loans acquired in transfer not accounted for as debt securities accretable yield discount.
Certain Loans Acquired in Transfer not Accounted for as Debt Securities Accretable Yield [Table Text Block]
The tabular disclosure of certain loans acquired in transfer not accounted for as debt securities accretable yield.
Adjustments to goodwill
Goodwill, Period Increase (Decrease)
us-gaap_LoansAndLeasesReceivableRelatedParties
Balance at December 31, 2015
Balance at December 31, 2016
Summary Of Purchased Impaired Loan Acquired [Table Text Block]
Summary of purchased impaired loan acquired.
ncom_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesPurchaseAdjustmentsAccretableYield
Purchase adjustments to United accretable yield
Amount of purchase adjustments to accretable yield in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.
Operating Segments [Member]
Intersegment Eliminations [Member]
Consolidation Items [Axis]
Consolidation Items [Domain]
Condensed Cash Flow Statement [Table Text Block]
Acquisition of Reunion
Goodwill, Acquired During Period
ncom_NumberOfSecuritiesInLossPosition
Number of Securities In Loss Position
The number of securities that are in loss position.
Notional amount
Cash flows from financing activities (net of effect of business combinations):
Business Combination Disclosure [Text Block]
Condensed Income Statement [Table Text Block]
Financing Receivable Credit Quality Indicators [Table Text Block]
Condensed Balance Sheet [Table Text Block]
us-gaap_ThresholdPeriodPastDueForWriteoffOfFinancingReceivable
Threshold Period Past Due for Write-off of Financing Receivable
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]
Current
Long-term Debt, Type [Axis]
us-gaap_PaymentsToAcquireLifeInsurancePolicies
Investment in bank-owned life insurance
Past Due
Long-term Debt, Type [Domain]
Quarterly Financial Information [Table Text Block]
us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Impaired loans
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivables, Period Past Due [Axis]
Investments Classified by Contractual Maturity Date [Table Text Block]
Financing Receivables, Period Past Due [Domain]
Schedule of Unrealized Loss on Investments [Table Text Block]
Past Due Financing Receivables [Table Text Block]
us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries
Capital injection in subsidiaries
us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Net cash (paid) received in acquisitions
Cash from merger of subsidiary
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Cash paid for shares and in lieu of fractional shares
Payments to Acquire Businesses, Gross
Cash paid in acquistion (including offering expenses)
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block]
us-gaap_FinitelivedIntangibleAssetsAcquired1
Finite-lived Intangible Assets Acquired
Outstanding FHLB Advance 2 [Member]
Refers to information regarding the second advance of outstanding federal home loan bank advances.
Quarterly Financial Information [Text Block]
Outstanding FHLB Advance 1 [Member]
Refers to information regarding the first advance of outstanding federal home loan bank advances.
Nonvoting Common Stock [Member]
Class of Stock [Axis]
Class of Stock [Domain]
Outstanding FHLB Advance 3 [Member]
Refers to information regarding the third advance of outstanding federal home loan bank advances.
us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities
Proceeds from Sale and Maturity of Marketable Securities
Proceeds from calls, maturities, paydowns of securities held-to-maturity
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Proceeds from sale of securities available-for-sale
Proceeds from calls, maturities, and paydowns of securities available-for-sale
us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt
Proceeds from Sale of Available-for-sale Securities, Debt
ncom_ExpenseBenefitOfNetOperatingLossCarryforward
Expense of operating loss carryforwards
Amount of expense (benefit) of net operating loss carryforward.
ncom_IncomeTaxReconciliationCashSurrenderValue
Cash surrender value income
Amount of cash surrender value income included in the reconciliation of income taxes.
Merger-related expenses
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to merger related expenses.
Fair Value Hedging [Member]
Hedging Relationship [Axis]
Proceeds from sale of other investments
Hedging Relationship [Domain]
Proceeds from sale of other real estate
ncom_DeferredTaxAssetsNonaccrualInterestIncome
Non-accrual interest income
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from non-accrual interest income.
Designated as Hedging Instrument [Member]
Not Designated as Hedging Instrument [Member]
Hedging Designation [Axis]
Hedging Designation [Domain]
us-gaap_PaymentsToAcquireOtherInvestments
Purchases of other investments
ncom_DeferredTaxAssetsOtherRealEstate
Other real estate
Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from other real estate.
Commitments to extend credit
Amount of commitments to extend credit.
us-gaap_PaymentsToAcquireAvailableForSaleSecurities
Purchases of securities available-for-sale
Financial instruments whose contract amounts represent credit risk:
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]
us-gaap_PaymentsToAcquireHeldToMaturitySecurities
Purchases of securities held-to-maturity
us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Debt Instrument, Basis Spread on Variable Rate
us-gaap_DebtInstrumentInterestRateStatedPercentage
Debt Instrument, Interest Rate, Stated Percentage
Fair value discounts
Transfer of loans to other real estate
Valuation Technique [Axis]
Valuation Technique [Domain]
Non-cash investing and financing activities:
Proceeds from the sale of premises and equipment
Income taxes
London Interbank Offered Rate (LIBOR) [Member]
Variable Rate [Axis]
Variable Rate [Domain]
2011 Equity Incentive Plan [Member]
Refers to information regarding the 2011 equity incentive plan.
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of premises and equipment
Fair Value Inputs, Assets, Quantitative Information [Table Text Block]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Dilutive effect of stock options (in shares)
Dilutive effect of directors' deferred shares (in shares)
Reported Value Measurement [Member]
Federal Home Loan Bank advances
Federal Home Loan Bank advances
us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Line of Credit Facility, Remaining Borrowing Capacity
Net income to common shareholders
Net earnings
Net earnings attributable to National Commerce Corporation
Net earnings attributable to National Commerce Corporation
Performance Shares [Member]
Employee Stock Option [Member]
Debt Disclosure [Text Block]
ncom_ClassOfWarrantIssued
Class Of Warrant Issued
The number of warrants issued.
us-gaap_PaymentsToAcquireFederalReserveStock
Payments to Acquire Federal Reserve Bank Stock
Fair Value, Measurements, Recurring [Member]
Fair Value, Measurements, Nonrecurring [Member]
Measurement Frequency [Axis]
Fair Value, Measurement Frequency [Domain]
Cash flows from investing activities (net of effect of business combinations):
Change in other liabilities
Property, Plant and Equipment Disclosure [Text Block]
Property, Plant and Equipment [Table Text Block]
Parent Company [Member]
Reclassification adjustment for losses included in net earnings, tax
Unrealized (losses) gains arising during the period, tax
ncom_ClassOfWarrantExercisablePeriod
Class of Warrant Exercisable Period
The exercisable period of warrants.
ncom_WarrantSharesVestedPeriod
Warrant Shares Vested Period
The vesting period of warrant shares.
ncom_SaleOfCommonStockPricePershare
Sale of Common Stock Price Per-share
The per share amount of the sale of common stock sale.
ncom_ProceedsFromIssuanceOfCommonStockNetOfferingExpenses
Proceeds from Issuance of Common Stock Net Offering Expenses
Proceeds from issuance of common stock net offering expenses.
ncom_WarrantOrRightExercisedInPeriod
Warrant Or Right Exercised In Period
The amount of warrants or rights that were exercised during the period.
Other liabilities and accrued interest payable
Liabilities assumed in acquisitions
us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure
Federal Home Loan Bank advances
Assets acquired in acquisitions
Subordinated debt
us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Assets acquired and liabilities assumed in acquisitions:
Exercise of Underwriters Option [Member]
Refers to information regarding the exercise of underwriters option.
ncom_FractionalSharesCashedOut
Fractional Shares Cashed Out
Adjustment for fractional shares.
ncom_CommonEquityTier1CapitalToRiskWeightedAssetsForCapitalAdequacyPurposesRatio
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Ratio
The common equity tier 1 capital (to risk weighted assets), for capital adequacy purposes, disclosed as a ratio
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income
National Bank of Commerce [Member]
Refers to the entity National Bank of Commerce.
Preferred stock, shares outstanding (in shares)
National Commerce Corporation [Member]
Refers to the entity National Commerce Corporation.
Estimate of Fair Value Measurement [Member]
Common stock, shares outstanding (in shares)
Portion at Fair Value Measurement [Member]
Common Equity Tier 1 Capital, Actual Amount
Common Equity Tier 1 Risk Based Capital as defined in the regulations.
Measurement Basis [Axis]
Subordinated Debt [Member]
us-gaap_AllocatedShareBasedCompensationExpense
Allocated Share-based Compensation Expense
us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Loans, individually evaluated for impairment
us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Loans, collectively evaluated for impairment
us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Allowance for loan losses, ending balance, collectively evaluated for impairment
us-gaap_IncreaseDecreaseInOtherOperatingAssets
Change in other assets
us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Allowance for loan losses, ending balance, individually evaluated for impairment
us-gaap_IncreaseDecreaseInDerivativeAssets
Change in mortgage loan derivative
Loans:
Recoveries
us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Loans charged off
Tax benefit resulting from exercise of stock options, net of adjustment
Receivables Acquired with Deteriorated Credit Quality [Domain]
Receivables Acquired with Deteriorated Credit Quality [Member]
Receivables Acquired with Deteriorated Credit Quality [Axis]
Allowance for Credit Losses on Financing Receivables [Table Text Block]
Share-based compensation expense
Standby and performance letters of credit
Letters of Credit Outstanding, Amount
Offering expenses
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs
us-gaap_IncreaseDecreaseInReceivables
Other assets and accrued interest receivable
Share repurchase and retirement
us-gaap_IncreaseDecreaseInFinanceReceivables
Net change in loans
Exercise of stock options and issuance of performance shares
Exercise of stock options and warrants
Acquisitions, net of operating expenses
us-gaap_LoansReceivableFairValueDisclosure
Loans, net
us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Exercised, shares (in shares)
Exercise of stock options
Fair Value, by Balance Sheet Grouping [Table Text Block]
Fair Value Disclosures [Text Block]
Other Investments [Policy Text Block]
Other investments policy.
Other Real Estate Owned and Repossessed Assets [Policy Text Block]
Other real estate owned and repossessed assets.
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod
Forfeited, shares (in shares)
Accumulated Other Comprehensive Income Policy [Policy Text Block]
Accumulated other comprehensive income policy.
Granted, shares (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross
Derivative Instruments and Hedging Activities [Policy Text Block]
Derivative instruments and hedging activities policy.
Mortgage Banking Derivatives Policy [Policy Text Block]
Mortgage banking derivatives, policy.
us-gaap_StockIssuedDuringPeriodSharesNewIssues
Stock Issued During Period, Shares, New Issues
ncom_NumberOfSecuritiesSold
Number of Securities Sold
The number of securities sold during the period,
Sale of common stock, net of offering expenses
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and shareholders' equity
Total liabilities and shareholders' equity
Retained earnings
Retained earnings
Accumulated other comprehensive income
Accumulated other comprehensive income
us-gaap_IncreaseDecreaseInMortgageLoansHeldForSale
Mortgage loans held-for-sale
us-gaap_DepositsFairValueDisclosure
Deposits
us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Class of Warrant or Right, Exercise Price of Warrants or Rights
us-gaap_ClassOfWarrantOrRightOutstanding
Class of Warrant or Right, Outstanding
Change in:
Fair value of asset
Forward Commitment to Sell Mortgage-backed Securities [Member]
Represents Forward Commitment to Sell Mortgage-backed Securities, a derivative instrument.
Deferred tax expense
Statement of Comprehensive Income [Abstract]
Deferred income tax (benefit) expense
Deferred
us-gaap_MortgagesHeldForSaleFairValueDisclosure
Mortgage loans held-for-sale
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Cash and cash equivalents
Share-based expense
Share-based compensation expense
Common stock, $0.01 par value, 30,000,000 shares authorized, 10,934,541 and 10,824,969 shares issued and outstanding at December 31, 2016 and December 31, 2015, respectively
Common stock
us-gaap_TableTextBlock
Notes Tables
Depreciation, amortization, and accretion
CBI Holding Company, LLC [Member]
Refers to information regarding the entity CBI Holding Inc.
Common stock, shares issued (in shares)
Common stock, shares authorized (in shares)
Common Stock, Shares Authorized
US Government Agencies Debt Securities [Member]
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share
Depreciation
Depreciation
Mortgage loans held-for-sale
Amount of mortgage loans held-for-sale, acquired at the acquisition date.
ncom_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedRepurchaseLiabilities
Repurchase liability
The amount of repurchase liabilities assumed (as defined) which have been recognized as of the acquisition date.
Preferred stock, 250,000 shares authorized, no shares issued or outstanding
Preferred stock, shares issued (in shares)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Preferred stock, shares authorized (in shares)
ncom_BusinessAcquisitionStockConversionRatio
Business Acquisition Stock, Conversion Ratio
Number of shares of the acquirer that each outstanding share of common stock of an acquiree was converted into upon the effectiveness of a business acquisition.
Commitments to Extend Credit [Member]
Converted to Shares [Member]
Refers to the conversion of shares to another unit.
ncom_PercentageOfMergedEntityAcquiredByIssuanceOfCommonStock
Percentage of Merged Entity Acquired by Issuance of Common Stock
Represents the percentage of the the issued and outstanding shares of the merged entity's common stock that was acquired by the reporting entity by means of issuance of the reporting entity's common stock.
ncom_PercentageOfCommonStockIssuedAndOutstandingOfAquireeForWhichCashPaymentsMayBeMade
Percentage of Common Stock Issued and Outstanding of Aquiree for Which Cash Payments May Be Made
Maximum percentage of common stock issued and outstanding of aquiree for which cash payments may be made.
ncom_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivablesDiscount
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Current Assets Receivables Discount
Discount from the amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.
Interest
ncom_NumberOfFullserviceBankingLocations
Number of Full-service Banking Locations
The number of full-service banking locations.
Option to Purchase [Member]
Refers to the information regarding the option to purchase.
us-gaap_OperatingLeasesFutureMinimumPaymentsDue
Total future minimum lease payments
ncom_TradeAccountsReceivableAverageCollectionPeriod
Trade Accounts Receivable Average Collection Period
Average period for collection for trade accounts receivable, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
ncom_NumberOfLoanProductionOffices
Number of Loan Production Offices
The number of loan production offices.
us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter
Thereafter
us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears
2020
us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears
2021
us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears
2018
us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears
2019
us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent
2017
Noncontrolling interest
Noncontrolling interest
Interest Rate Swap [Member]
us-gaap_DerivativeGainOnDerivative
Derivative, Gain on Derivative
us-gaap_AdditionalPaidInCapital
Additonal paid-in capital
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio
Common Equity Tier 1 capital divided by risk weighted assets as defined by regulations.
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Ratio
The minimum Common Equity Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.
Additional paid-in capital
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well-Capitalized, Ration
The Common Equity Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.
Shareholders’ equity:
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well-Capitalized, Amount
The amount of Common Equity Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.
Cash flows from operating activities:
Statement [Line Items]
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Amount
The minimum amount of Common Equity Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.
Financial Instrument [Axis]
Financial Instruments [Domain]
AOCI Attributable to Parent [Member]
Other Commitments [Table Text Block]
Schedule of Derivative Instruments [Table Text Block]
us-gaap_Liabilities
Total liabilities
Total liabilities
Commitments and contingencies
Other liabilities
Other liabilities
us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
Other comprehensive (loss) income
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 3 [Member]
Fair Value Hierarchy [Domain]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]
Fair Value, Inputs, Level 1 [Member]
Fair Value, Hierarchy [Axis]
Derivative liabilities
Derivative Liability
Derivative liabilities
Accrued interest payable
Available-for-Sale Securities, Gross Unrealized Gains
Noncontrolling Interest [Member]
Available-for-Sale Securities, Gross Unrealized Losses
Available-for-Sale Securities, Amortized Cost
Available-for-sale Securities, Amortized Cost
us-gaap_StockholdersEquity
Total shareholders' equity attributable to National Commerce Corporation
Total shareholders' equity attributable to National Commerce Corporation
Retained Earnings [Member]
Change in unrealized (losses) gains on securities available-for-sale, net of tax
Available-for-sale Securities, 12 Months or More, Unrealized Losses
Available-for-sale Securities, Total Unrealized Losses
Additional Paid-in Capital [Member]
Reclassification adjustment for losses included in net earnings, net of tax of $12 in 2014
Available-for-sale Securities, Less than 12 Months, Unrealized Losses
Change in unrealized gain/loss on securities available-for-sale, sale, net of tax
Unrealized (losses) gains arising during the period, net of tax of $(160), $(160) and $287, respectvely
Common Stock [Member]
Equity Components [Axis]
Equity Component [Domain]
Other Liabilities [Member]
Other Assets [Member]
Available-for-sale Securities, 12 Months or More, Fair Value
Available-for-sale Securities, Total Fair Value
Available-for-sale Securities, Less than 12 Months, Fair Value
Other comprehensive income (loss), net of tax:
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue
Mortgage-backed securities and other asset-backed securities
Subordinated debt
us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Total shareholders' equity
Total shareholders' equity
Balance
Balance
Automobiles [Member]
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
Available-for-sale Securities, Fair Value, 5 to 10 years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
Available-for-sale Securities, Fair Value, Over 10 years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Available-for-sale Securities, Fair Value, 0 to 5 years
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost
Mortgage-backed securities and other asset-backed securities
Computer Equipment [Member]
Balance Sheet Location [Domain]
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
Available-for-sale Securities, Amortized Cost, Over 10 years
Exercisable, end of year, weighted average exercise price (in dollars per share)
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
Available-for-sale Securities, Amortized Cost, 0 to 5 years
Third Party Appraisals, Sales Contracts, Broker Price Opinions [Member]
The valuation technique of third party appraisals, sales contracts and broker price opinions.
Balance Sheet Location [Axis]
us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
Available-for-sale Securities, Amortized Cost, 5 to 10 years
Exercisable, end of year, shares (in shares)
Other Real Estate [Member]
Fair value of other real estate and foreclosed assets.
Third Party Appraisals and Discounted Cash Flows [Member]
The valuation technique for third party appraisals and discounted cash flows.
us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term
Impaired Loans [Member]
Fair value of impaired loans.
us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Available-for-sale Securities, Gross Realized Gains
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
Outstanding, beginning of year, weighted average exercise price (in dollars per share)
Oustanding, end of year, weighted average exercise price (in dollars per share)
Assumed, weighted average exercise price (in dollars per share)
Other Income [Member]
Forfeited, weighted average exercise price (in dollars per share)
Granted, weighted average exercise price (in dollars per share)
Exercised, weighted average exercise price (in dollars per share)
Income Statement Location [Domain]
Weighted Average [Member]
Income Statement Location [Axis]
Maximum [Member]
Minimum [Member]
Range [Axis]
Range [Domain]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
Outstanding, beginning of year, shares (in shares)
Oustanding, end of year, shares (in shares)
Assumed, shares (in shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Other Increases (Decreases) in Period
us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroupMortgage
Mortgage loans held-for-sale
US States and Political Subdivisions Debt Securities [Member]
Debt Securities [Member]
Major Types of Debt and Equity Securities [Axis]
Major Types of Debt and Equity Securities [Domain]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized
Available-for-sale Securities [Table Text Block]
us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period
Compensation and Employee Benefit Plans [Text Block]
Plan Name [Axis]
Plan Name [Domain]
New loans
us-gaap_LoansAndLeasesReceivableRelatedPartiesProceeds
Repayments
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options
us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options
Geographical [Axis]
Award Type [Axis]
Geographical [Domain]
Equity Award [Domain]
Successor [Member]
Predecessor [Member]
Scenario, Forecast [Member]
Scenario, Unspecified [Domain]
Scenario [Axis]
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]
us-gaap_Deposits
Total deposits
Deposits
Segments [Axis]
us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders
Distributions paid to noncontrolling interest
Segments [Domain]
Interest-bearing demand
Noninterest-bearing demand
Statement [Table]
Time
Total time deposits
Savings and money market
Commitments and Contingencies Disclosure [Text Block]
Net income attributable to minority interest
Less: Net earnings attributable to noncontrolling interest
Noncontrolling interest
Income Statement [Abstract]
Initial noncontrolling interest
Derivative Contract [Domain]
Derivative Instrument [Axis]
Federal Home Loan Bank Advances [Member]
ncom_OtherInvestmentsFairValueDisclosure
Other investments
Fair value portion of amount of investments classified as other.
ncom_BankOwnedLifeInsuranceFairValueDisclosure
Bank-owned life insurance
Fair value portion of life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy.
Reclassification for Delaware reincorporation
Short-term Debt, Type [Axis]
Short-term Debt, Type [Domain]
Net income before minority interest
us-gaap_ProfitLoss
Net earnings
us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue
Security Owned and Pledged as Collateral, Fair Value
Income tax expense
Income tax expense
Total income tax expense
Income tax benefit
Income tax expense
Equity in undistributed earnings of subsidiaries
Equity in undistributed earnings of subsidiaries
Collateralized Mortgage Backed Securities [Member]
Loss before equity in undistributed earnings of subsidiaries
Asset-backed Securities [Member]
us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net
Loss on sale of investment securities available-for-sale
Loss on sale of investment securities available-for-sale
Non-accretable difference
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodAtAcquisitionAtFairValue
Fair value of loans acquired with a deterioration of credit quality
us-gaap_GainLossOnSaleOfDerivatives
(Gain) loss on ineffective portion of fair value hedge derivative
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodCommercialCashFlowsExpectedToBeCollectedAtAcquisition
Cash flows expected to be collected
Contractually required principal and interest payments
Commission-based compensation
The amount of expense related to commission based compensation.
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield
Balance, beginning of year
Balance, end of year
Tier 1 Capital (to Average Assets), For Capital Adequacy Purposes, Ratio
Tier One Leverage Capital Required for Capital Adequacy to Average Assets
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsToFromNonaccretableDifference
Net transfers from non-accretable difference to accretable yield
Tier 1 Leverage Capital (to Average Assets), To Be Well-Capitalized, Ration
us-gaap_GainLossOnSaleOfSecuritiesNet
Gain (Loss) on Sale of Securities, Net
Tier 1 Leverage Capital (to Average Assets), Actual Ratio
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions
Acquisition
Total Capital (to Risk Weighted Assets), To Be Well-Capitalized, Ration
us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion
Accretion
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
Total Capital (to Risk Weighted Assets), Actual Ratio
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Defined Contribution Plan, Employer Matching Contribution, Percent of Match
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Ratio
Capital Required for Capital Adequacy to Risk Weighted Assets
us-gaap_MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments
Marketable Securities, Realized Gain (Loss), Excluding Other than Temporary Impairments
us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Ratio
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets
Tier 1 Capital (to Risk Weighted Assets), To Be Well-Capitalized, Ration
us-gaap_DefinedContributionPlanCostRecognized
Defined Contribution Plan, Cost Recognized
Tier 1 Capital (to Risk Weighted Assets), Actual Ratio
Total Capital (to Risk Weighted Assets), To Be Well-Capitalized, Amount
Total Capital, Actual Amount
Total Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Amount
us-gaap_OperatingExpenses
Total expenses
Other expense
Tier 1 Leverage Capital (to Average Assets), For Capital Adequacy Purposes, Amount us-
Tier 1 Leverage Capital (to Average Assets), To Be Well-Capitalized, Amount
Tier 1 Leverage Capital, Actual Amount
Tier 1 Capital (to Risk Weighted Assets), To Be Well-Capitalized, Amount
Tier 1 Capital, Actual Amount
Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy Purposes, Amount
Unpaid Recourse Receivables [Member]
Represents unpaid recourse receivables.
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]
us-gaap_LeaseAndRentalExpense
Operating Leases, Rent Expense
Subsequent Event [Member]
Non-recourse Receivables [Member]
Represents non-recourse receivables.
Salaries and employee benefits
Subsequent Event Type [Axis]
Subsequent Event Type [Domain]
Regulatory Capital Requirements under Banking Regulations [Text Block]
Commercial, Financial and Agricultural Portfolio Segment [Member]
Portfolio segment of the company's total financing receivables related to commercial, financial and agricultural receivables.
Factored Commercial Receivables Portfolio Segment [Member]
Portfolio segment of the company's total financing receivables related to factored commercial receivables receivables.
Subsequent Events [Text Block]
Real Estate Portfolio Segment [Member]
Portfolio segment of the company's total financing receivables related to real estate financing receivables.
Mortgage Loans [Member]
A loan to finance the purchase of real estate where the lender has a lien on the property as collateral for the loan.
ncom_FederalFundsSoldPeriod
Federal Funds Sold Period
Represents the federal funds sold period.
Reunion Bank of Florida [Member]
The entity Reunion Bank of Florida.
ncom_FundingCostsOfFederalsFundsPercentage
Funding Costs of Federals Funds, Percentage
Represents the funding costs of federals funds percentage.
Gain (loss) on other real estate
(Gain) loss on other real estate
us-gaap_GainLossOnSaleOfPropertyPlantEquipment
Loss on trade or sale of premises and equipment
Retail and Commercial Banking [Member]
Information pertaining to the retail and commercial banking segment.
Standby Letters of Credit [Member]
Receivables Factoring [Member]
Information pertaining to the receivables factoring segment.
Mortgage Division [Member]
Information pertaining to the mortgage division segment.
Held-to-maturity Securities, Total Fair Value
Held-to-maturity Securities, Less than 12 Months, Fair Value
Held-to-maturity Securities, 12 Months or More, Fair Value
us-gaap_BusinessCombinationIntegrationRelatedCosts
Business Combination, Integration Related Costs
Liabilities and Shareholders’ Equity
us-gaap_Assets
Total assets
Total assets
us-gaap_BusinessCombinationAcquisitionRelatedCosts
Business Combination, Acquisition Related Costs
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue
Mortgage-backed securities and other asset-backed securities
Other real estate non-cash write downs
Deferred tax assets, net
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount
Mortgage-backed securities and other asset-backed securities
us-gaap_SharesIssuedPricePerShare
Shares Issued, Price Per Share
Stockholders' Equity Note Disclosure [Text Block]
us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
Held-to-maturity Securities, Fair Value, 5 to 10 years
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
Held-to-maturity Securities, Fair Value, Over 10 years
us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged
Other assets
Other assets
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
Held-to-maturity Securities, Fair Value, 0 to 5 years
Converted to Cash [Member]
Refers to information regarding conversions to cash.
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
Held-to-maturity Securities, Amortized Cost, 5 to 10 years
Florida [Member]
Refers to information regarding the state of Florida.
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
Held-to-maturity Securities, Amortized Cost, Over 10 years
Core deposit intangible amortization
us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
Held-to-maturity Securities, Amortized Cost, 0 to 5 years
Other Non-Interest Expenses [Member]
Refers to information regarding non-interest expense.
us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Finite-Lived Intangible Assets, Accumulated Amortization
Less: accumulated amortization
Core deposit intangible, net
Total amortization expense
ncom_NumberOfSecurities
Number of Securities
The number of securities.
Gross carrying amount
Current rate
Held-to-maturity Securities, 12 Months or More, Unrealized Losses
Advance
Held-to-maturity Securities, Less than 12 Months, Unrealized Losses
Held-to-maturity Securities, Total Unrealized Losses
Held-to-Maturity Securities, Gross Unrealized Losses
us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Held-to-Maturity Securities, Gross Unrealized Gains
Occupancy and equipment
Held-to-maturity Securities [Table Text Block]
Federal Home Loan Bank Branch [Axis]
Federal Home Loan Bank Branch [Domain]
Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block]
Goodwill
Goodwill
Balance
Balance
Federal Home Loan Bank Advances, Disclosure [Text Block]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Less: accumulated depreciation
Premises and equipment, net
Total premises and equipment, net
Schedule of Contractual Maturities of Time Deposits [Table Text Block]
Tabular disclosure of contractual maturities of time deposits.
Premises and equipment gross
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Text Block]
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
Derivative assets
Derivative assets
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]
us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet
Mortgage loans held-for-sale
Other noninterest expense (1)
us-gaap_OtherCostAndExpenseOperating
Other
ncom_BusinessAcquisitionNumberOfSharesOfAcquiringEntityForEachShareOfAcquiredEntity
Business Acquisition, Number of Shares of Acquiring Entity for Each Share of Acquired Entity
Represents the number of shares of the acquiring entity into which the shares of the acquired entity may be converted pursuant to a definitive agreement.
Investment securities held-to-maturity
Held-to-maturity securities, fair value
Investment securities held-to-maturity
Acquisition of Private Bancshares [Member]
Represents information pertaining to the acquisition of Private Bancshares, Inc., the parent company of Private Bank of Buckhead, with and into NCC.
Investment securities held-to-maturity (fair value of $25,894 and $27,843 at December 31, 2016 and December 31, 2015, respectively)
Held-to-maturity Securities
us-gaap_WeightedAverageRateDomesticDepositBrokered
Weighted Average Rate Domestic Deposit, Brokered
New Accounting Pronouncements, Policy [Policy Text Block]
Reclassification, Policy [Policy Text Block]
us-gaap_NumberOfReportableSegments
Number of Reportable Segments