Fair Value Disclosures [Abstract] Financial assets and liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Reconciliation of the beginning and ending balances for the liabilities measured at fair value using significant unobservable inputs Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Reconciliation of the beginning and ending balances for the assets measured at fair value using significant unobservable inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill roll-forward: Goodwill [Roll Forward] Balance at beginning of period Goodwill Command acquisition, purchase price adjustment Goodwill, Purchase Accounting Adjustments Balance at end of period Accounting Policies [Abstract] Preparation of Financial Statements and Use of Estimates Use of Estimates, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Earnings Per Share [Abstract] Computation of basic and diluted earnings per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Related Party Transactions [Abstract] Related Parties Related Party Transactions Disclosure [Text Block] Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Command Transportation, LLC Command Transportation, LLC [Member] Command Transportation, LLC [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships Customer Relationships [Member] Carrier relationships Carrier Relationships [Member] Carrier Relationships [Member] Trade names Trade Names [Member] Noncompete agreements Noncompete Agreements [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Value Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Useful Life Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Debt Disclosure [Abstract] Schedule of convertible senior notes Schedule of Long-term Debt Instruments [Table Text Block] Schedule of maturities of convertible senior notes Schedule of Maturities of Long-term Debt [Table Text Block] Fair value of total consideration transferred for Command Schedule of Business Acquisitions, by Acquisition [Table Text Block] Allocation of the total consideration transferred for Command Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Fair values assigned to intangible assets acquired for Command Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] Earnings Per Share Earnings Per Share [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-Based Compensation Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted stock Restricted Stock [Member] Performance and market-based stock Performance and Market Based Stock [Member] Performance and Market Based Stock [Member] Stock based compensation plans: Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock-based compensation expense Allocated Share-based Compensation Expense Tax benefits from stock-based compensation expense Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Grants in period, options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Grants in period, other than options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Cash Payments to Acquire Businesses, Gross Echo common stock, fair value Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Contingent consideration, fair value Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset Working capital adjustment Total consideration transferred Business Combination, Consideration Transferred Roll-forward of goodwill Schedule of Goodwill [Table Text Block] Summary of amortizable intangible assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Estimated amortization expense for the next five years and thereafter Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Contingent consideration Contingent Consideration [Member] Contingent Consideration [Member] Performance Shares Performance Shares [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Sellers with new Employment Agreements Management [Member] Fair value of total consideration transferred Equity portion of purchase price (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Echo share price (in usd per share) Business Acquisition, Share Price Marketability discount percentage applied Fair Value Inputs, Discount for Lack of Marketability Goodwill Contingent asset due from seller Contingent consideration receivable Receivables, Fair Value Disclosure Receipt of contingent consideration due from seller Proceeds from Collection of Other Receivables Number of employees granted shares Share-based Compensation Arrangement by Share-based Payment Award, Number of Employees Granted Shares Share-based Compensation Arrangement by Share-based Payment Award, Number of Employees Granted Shares Award vesting period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Number of shares of restricted common stock and performance stock outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Liabilities: Liabilities, Fair Value Disclosure [Abstract] Contingent consideration due to seller Obligations, Fair Value Disclosure Assets: Assets, Fair Value Disclosure [Abstract] Contingent consideration due from seller Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Director Director [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Minimum monthly rental payments Operating Lease, Minimum Monthly Rental Payments Operating Lease, Minimum Monthly Rental Payments Rent expense Operating Leases, Rent Expense Liability due to related party Due to Related Parties Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Selling, general and administrative expenses Selling, General and Administrative Expenses [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Contingent consideration due to seller Probability of reaching the forecast (as a percent) Business Acquisition, Contingent Consideration, Forecast Probability Business Acquisition, Contingent Consideration, Forecast Probability Discount rate used to determine fair value of contingent consideration Business Acquisition, Contingent Consideration, Discount Rate Used to Determine Fair Value Business Acquisition, Contingent Consideration, Discount Rate Used to Determine Fair Value Change in fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) Payments of contingent consideration due to seller Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Cash Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Accounts receivable, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Prepaid expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Intangible assets Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accrued Expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accrued Expenses Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Total consideration transferred Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Statement of Financial Position [Abstract] Current assets: Assets, Current [Abstract] Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Customer relationships and other intangible assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock, par value (in usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock, shares (in shares) Treasury Stock, Shares Long-Term Debt Debt Disclosure [Text Block] Income Tax Disclosure [Abstract] Reconciliation of effective income tax rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] State Tax Audit [Member] State Tax Audit [Member] State Tax Audit [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Amount of assessment including penalties and interest Loss Contingency, Estimate of Possible Loss Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Change in contingent consideration due to seller Balance at end of period Payables and Accruals [Abstract] Accrued compensation Accrued Salaries, Current Accrued rebates Accrued Rebates, Current Accrued Rebates Accrued employee benefits Accrued Employee Benefits Accrued professional service fees Accrued Professional Fees Accrued interest Interest Payable, Current Deferred rent Deferred Rent Credit, Current Other Other Accrued Liabilities, Current Total accrued expenses Accrued Liabilities, Current Other noncurrent liabilities Other Liabilities, Noncurrent Contingencies Legal Matters and Contingencies [Text Block] Assets Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, net of allowance for doubtful accounts of $1,507,016 and $1,627,315 at September 30, 2016 and December 31, 2015, respectively Accounts Receivable, Net, Current Income taxes receivable Income Taxes Receivable, Current Prepaid expenses Prepaid Expense, Current Other current assets Other Assets, Current Total current assets Assets, Current Noncurrent assets: Assets, Noncurrent [Abstract] Property and equipment, net Property, Plant and Equipment, Net Intangible assets, net of accumulated amortization of $38,680,343 and $26,785,810 at September 30, 2016 and December 31, 2015, respectively Intangible Assets, Net (Excluding Goodwill) Other noncurrent assets Other Assets, Noncurrent Total noncurrent assets Assets, Noncurrent Total assets Assets Liabilities and stockholders' equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Trade, Current Due to seller, current Business Acquisition Contingent Consideration at Reporting Period Fair Value Current Current portion of the fair value, as of the financial statement date, of potential payments under the contingent consideration arrangement, including cash and shares as applicable. Accrued expenses Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Noncurrent liabilities: Liabilities, Noncurrent [Abstract] Convertible notes, net Convertible Notes Payable Due to seller, noncurrent Business Acquisition Contingent Consideration at Reporting Period Fair Value Noncurrent Noncurrent portion of the fair value as of the acquisition date of potential payments under the contingent consideration arrangement, including cash and shares as applicable. Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Total noncurrent liabilities Liabilities, Noncurrent Total liabilities Liabilities Common stock, par value $0.0001 per share, 100,000,000 shares authorized, 30,351,479 shares issued and 28,635,197 shares outstanding at September 30, 2016; 29,765,525 shares issued and 29,727,588 shares outstanding at December 31, 2015 Common Stock, Value, Issued Treasury stock, 1,716,282 and 37,937 shares at September 30, 2016 and December 31, 2015, respectively Treasury Stock, Value Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders' equity Liabilities and Equity Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Customer relationships Intangible assets: Finite-Lived Intangible Assets [Line Items] Summary of amortizable intangible assets: Finite-Lived Intangible Assets, Net [Abstract] Finite-lived intangible assets, gross Finite-Lived Intangible Assets, Gross Less accumulated amortization Intangible assets, net Finite-Lived Intangible Assets, Net Weighted-Average Life (in years) Finite-Lived Intangible Asset, Useful Life Amortization of expense Amortization of Intangible Assets Estimated amortization expense for the next five years and thereafter: Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract] Remainder of 2016 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Five Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Letter of Credit Letter of Credit [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] ABL Facility ABL Facility [Member] ABL Facility [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Federal Funds Effective Rate Federal Funds Effective Swap Rate [Member] LIBOR London Interbank Offered Rate (LIBOR) [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Increase to borrowing capacity Line of Credit Facility, Increase to Maximum Borrowing Capacity Line of Credit Facility, Increase to Maximum Borrowing Capacity Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Basis spread on variable rate (as a percent) Debt Instrument, Basis Spread on Variable Rate Commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Interest expense Interest Expense, Debt Repayments of amounts borrowed on ABL facility Repayments of Long-term Debt Letters of credit outstanding Letters of Credit Outstanding, Amount Remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Issuance costs Payments of Debt Issuance Costs Life of ABL facility (in years) Debt Instrument, Term Amortization of debt issuance costs Amortization of Debt Issuance Costs Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Treasury Stock Treasury Stock [Member] Retained Earnings Retained Earnings [Member] Financial statements: Statement [Line Items] Increase (decrease) in stockholders' equity: Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance at beginning of period (in shares) Shares, Outstanding Balance at beginning of period Treasury stock at beginning of period (in shares) Share compensation expense Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Exercise of stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Common stock issued for vested restricted stock (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Common stock issued for vested restricted stock Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Common stock issued for vested performance shares (in shares) Stock Issued During Period, Shares, Share-based Compensation, Gross Common stock issued for vested performance shares Stock Issued During Period, Value, Share-based Compensation, Gross Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of share-based awards (in shares) Shares Paid for Tax Withholding for Share Based Compensation Common shares withheld and retired to satisfy employee tax withholding obligations upon vesting of share-based awards Adjustments Related to Tax Withholding for Share-based Compensation Tax deficiency from exercise of stock options Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation Purchases of treasury stock (in shares) Treasury Stock, Shares, Acquired Purchases of treasury stock Treasury Stock, Value, Acquired, Cost Method Net income Net Income (Loss) Attributable to Parent Balance at end of period (in shares) Balance at end of period Treasury stock at end of period (in shares) Accrued Expenses and Other Noncurrent Liabilities Accounts Payable and Accrued Liabilities Disclosure [Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Command purchase price adjustment Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Receipt of contingent consideration due from seller Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Change in contingent consideration due from seller Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Period Increase (Decrease) Balance at end of period Fair Value Measurement Fair Value Disclosures [Text Block] Numerator Earnings Per Share, Numerator [Abstract] Earnings Per Share, Numerator [Abstract] Net income Denominator: Earnings Per Share, Denominator [Abstract] Earnings Per Share, Denominator [Abstract] Denominator for basic earnings per common share - weighted-average shares (in shares) Weighted Average Number of Shares Outstanding, Basic Effect of dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Employee stock awards (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Denominator for dilutive earnings per common share (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic earnings per common share (in usd per share) Earnings Per Share, Basic Diluted earnings per common share (in usd per share) Earnings Per Share, Diluted Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock options Employee Stock Option [Member] Unvested restricted stock Anti-dilutive securities excluded from the calculation of earnings per share: Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Stock options excluded from the calculation of diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Components of accrued expenses Schedule of Accrued Liabilities [Table Text Block] Income Taxes Income Tax Disclosure [Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior convertible notes, including interest Senior Notes [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Conversion ratio Debt Instrument, Convertible, Conversion Ratio Conversion price (in usd per share) Debt Instrument, Convertible, Conversion Price Straight debt borrowing rate Debt Instrument, Interest Rate, Straight Debt Borrowing Rate Debt Instrument, Interest Rate, Straight Debt Borrowing Rate Fair value of liability component Debt Instrument, Convertible, Carrying Amount of Debt Component Debt Instrument, Convertible, Carrying Amount of Debt Component Fair value of equity component Debt Instrument, Convertible, Carrying Amount of Equity Component Discount amortization period Debt Instrument, Convertible, Remaining Discount Amortization Period Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Carrying amount of Notes on the balance sheet: Long-term Debt, Other Disclosures [Abstract] Convertible senior notes, principal amount Debt Instrument, Face Amount Unamortized debt discount Debt Instrument, Unamortized Discount Unamortized debt issuance costs Unamortized Debt Issuance Expense Convertible senior notes, net Debt Instrument, Net of Debt Discount and Issuance Costs Debt Instrument, Net of Debt Discount and Issuance Costs Convertible senior notes, fair value Debt Instrument, Fair Value Disclosure Contractual coupon interest Interest Expense, Debt, Excluding Amortization Debt discount amortization Amortization of Debt Discount (Premium) Statement of Cash Flows [Abstract] Operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Deferred income taxes Deferred Income Tax Expense (Benefit) Noncash stock compensation expense Share-based Compensation Noncash interest expense Other Noncash Expense Change in contingent consideration due to seller Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Change in contingent consideration due from seller Depreciation and amortization Depreciation, Depletion and Amortization Change in assets, net of acquisitions: Increase (Decrease) in Operating Assets [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Income taxes receivable Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Change in liabilities, net of acquisitions: Increase (Decrease) in Operating Liabilities [Abstract] Accounts payable Increase (Decrease) in Accounts Payable Accrued expenses and other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Payments for acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Tax benefit of stock options exercised Deferred Tax Expense from Stock Options Exercised Payments of contingent consideration due to seller Payments of Merger Related Costs, Financing Activities Proceeds from exercise of stock options Proceeds from Stock Options Exercised Employee tax withholdings related to net share settlements of equity-based awards Payments Related to Tax Withholding for Share-based Compensation Purchases of treasury stock Payments for Repurchase of Equity Proceeds from borrowing on line of credit Proceeds from Lines of Credit Repayments of amounts borrowed on line of credit Repayments of Lines of Credit Proceeds from borrowing on ABL facility Proceeds from Issuance of Long-term Debt Repayments of amounts borrowed on ABL facility Proceeds from sale of common stock, net of underwriting discounts and commissions Proceeds from Issuance of Common Stock Proceeds from issuance of convertible notes, net of underwriting discounts and commissions Proceeds from Convertible Debt Payment of common stock and debt issuance costs Payment of Financing and Stock Issuance Costs Payment to former owners of One Stop Logistics Payment to Former Owners of Acquired Business Payment to Former Owners of Acquired Business Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities (Decrease) Increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental disclosure of cash flow information Supplemental Cash Flow Information [Abstract] Cash paid during the year for interest Interest Paid Cash paid for income taxes Income Taxes Paid Noncash investing activity Non-cash investing activity [Abstract] Non-cash investing activity [Abstract] Issuance of common stock in connection with Command acquisition Noncash or Part Noncash Acquisition, Equity Instrument Consideration, Value of Shares Issued Noncash or Part Noncash Acquisition, Equity Instrument Consideration, Value of Shares Issued Noncash financing activity Noncash Investing and Financing Items [Abstract] Fair value of due to seller obligation at acquisition date Contingent Earnout Payments Increase Due to New Acquisitions Contingent Earnout Payments, Increase Due to New Acquisitions Liability for purchases of treasury stock not yet settled Liability for Purchase of Treasury Stock Liability for Purchase of Treasury Stock Income before provision for income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Effective tax rate Effective Income Tax Rate Reconciliation, Percent Federal tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Income Statement [Abstract] Revenue Transportation Services Revenue The total dollar amount of transportation and transportation-related services charged to customers during the period. Costs and expenses: Costs and Expenses [Abstract] Transportation costs Cost of Purchased Transportation and Related Services The total costs of purchased transportation and transportation-related services to meet customer needs during the period. Selling, general and administrative expenses Selling, General and Administrative Expense Income from operations Operating Income (Loss) Interest income Interest Income, Other Interest expense Other expense Other Nonoperating Income (Expense) Interest and other expense Other Expense Other Expense is the aggregate of interest income, interest expense, and other income and expenses. Income before provision for income taxes Income tax expense Net income Earnings per common share: Basic (in usd per share) Diluted (in usd per share) New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Recent Accounting Pronouncements New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Intangibles and Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Acquisitions Business Combination Disclosure [Text Block] Total Long-term Debt 2016 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2017 Long-term Debt, Maturities, Repayments of Principal in Year Two 2018 Long-term Debt, Maturities, Repayments of Principal in Year Three 2019 Long-term Debt, Maturities, Repayments of Principal in Year Four 2020 Long-term Debt, Maturities, Repayments of Principal in Year Five