| Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] |
The table below presents the financial instrument's fair value and the amounts within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement:
| | | | | | | | | | | | | | | | | | | | | Fair Value of Assets and Liabilities Measured on a Recurring and Nonrecurring Basis | | | | Fair Value Measurements at Reporting Date Using: | Fair Value of Assets and Liabilities Measured on a Recurring Basis: | Fair Value | | Quoted Prices In Active Markets for Identical Assets (Level 1) | | Significant Other Observable Inputs (Level 2) | | Significant Unobservable Inputs (Level 3) | | Total Gains (Losses) | December 31, 2015 | | | | | | | | | | Securities Available-for Sale: | | | | | | | | | | U.S. Agency Obligations | $ | 155,782 |
| | $ | — |
| | $ | 155,782 |
| | $ | — |
| | | State and Municipal Obligations | 52,408 |
| | — |
| | 52,408 |
| | — |
| | | Mortgage-Backed Securities - Residential | 178,588 |
| | — |
| | 178,588 |
| | — |
| | | Corporate and Other Debt Securities | 14,299 |
| | — |
| | 14,299 |
| | — |
| | | Mutual Funds and Equity Securities | 1,232 |
| | — |
| | 1,232 |
| | — |
| | | Total Securities Available-for-Sale | $ | 402,309 |
| | $ | — |
| | $ | 402,309 |
| | $ | — |
| |
|
| December 31, 2014 | | | | | | | | | | Securities Available-for Sale: | | | | | | | | | | U.S. Agency Obligations | $ | 137,603 |
| | $ | — |
| | $ | 137,603 |
| | $ | — |
| | | State and Municipal Obligations | 81,730 |
| | — |
| | 81,730 |
| | — |
| | | Mortgage-Backed Securities - Residential | 128,827 |
| | — |
| | 128,827 |
| | — |
| | | Corporate and Other Debt Securities | 16,725 |
| | — |
| | 16,725 |
| | — |
| | | Mutual Funds and Equity Securities | 1,254 |
| | — |
| | 1,254 |
| | — |
| | | Total Securities Available-for Sale | $ | 366,139 |
| | $ | — |
| | $ | 366,139 |
| | $ | — |
| |
|
| | | | | | | | | | | Fair Value of Assets and Liabilities Measured on a Nonrecurring Basis: | | | | | | | | | | December 31, 2015 | | | | | | | | | | Collateral Dependent Impaired Loans | $ | — |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | — |
| Other Real Estate Owned and Repossessed Assets, Net | $ | 2,018 |
| | $ | — |
| | $ | — |
| | $ | 2,018 |
| | $ | (687 | ) | December 31, 2014 | | | | | | | | | | Collateral Dependent Impaired Loans | $ | 574 |
| | $ | — |
| | $ | — |
| | $ | 574 |
| | $ | (109 | ) | Other Real Estate Owned and Repossessed Assets, Net | $ | 393 |
| | $ | — |
| | $ | — |
| | $ | 393 |
| | $ | (15 | ) |
|
| Fair Value, by Balance Sheet Grouping [Table Text Block] |
Fair Value by Balance Sheet Grouping
The following table presents a summary of the carrying amount, the fair value or an amount approximating fair value and the fair value hierarchy of Arrow’s financial instruments: | | | | | | | | | | | | | | | | | | | | | Schedule of Fair Values by Balance Sheet Grouping | | | | | | Fair Value Hierarchy | | Carrying Amount | | Fair Value | | Level 1 | | Level 2 | | Level 3 | December 31, 2015 | | | | | | | | | | Cash and Cash Equivalents | $ | 51,068 |
| | $ | 51,068 |
| | $ | 51,068 |
| | $ | — |
| | $ | — |
| Securities Available-for-Sale | 402,309 |
| | 402,309 |
| | — |
| | 402,309 |
| | — |
| Securities Held-to-Maturity | 320,611 |
| | 325,930 |
| | — |
| | 325,930 |
| | — |
| Federal Home Loan Bank and Federal Reserve Bank Stock | 8,839 |
| | 8,839 |
| | 8,839 |
| | — |
| | — |
| Net Loans | 1,557,914 |
| | 1,557,511 |
| | — |
| | — |
| | 1,557,511 |
| Accrued Interest Receivable | 6,360 |
| | 6,360 |
| | 6,360 |
| | — |
| | — |
| Deposits | 2,030,423 |
| | 2,024,224 |
| | 1,840,606 |
| | 183,618 |
| | — |
| Federal Funds Purchased and Securities Sold Under Agreements to Repurchase | 23,173 |
| | 19,421 |
| | 19,421 |
| | — |
| | — |
| Federal Home Loan Bank Term Advances | 137,000 |
| | 137,063 |
| | 82,000 |
| | 55,063 |
| | — |
| Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts | 20,000 |
| | 20,000 |
| | — |
| | 20,000 |
| | — |
| Accrued Interest Payable | 231 |
| | 231 |
| | 231 |
| | — |
| | — |
| | | | | | | | | | | December 31, 2014 | | | | | | | | | | Cash and Cash Equivalents | $ | 46,295 |
| | $ | 46,295 |
| | $ | 46,295 |
| | $ | — |
| | $ | — |
| Securities Available-for-Sale | 366,139 |
| | 366,139 |
| | — |
| | 366,139 |
| | — |
| Securities Held-to-Maturity | 302,024 |
| | 308,566 |
| | — |
| | 308,566 |
| | — |
| Federal Home Loan Bank and Federal Reserve Bank Stock | 4,851 |
| | 4,851 |
| | 4,851 |
| | — |
| | — |
| Net Loans | 1,397,698 |
| | 1,405,454 |
| | — |
| | — |
| | 1,405,454 |
| Accrued Interest Receivable | 5,834 |
| | 5,834 |
| | 5,834 |
| | — |
| | — |
| Deposits | 1,902,948 |
| | 1,899,682 |
| | 1,697,105 |
| | 202,577 |
| | — |
| Federal Funds Purchased and Securities Sold Under Agreements to Repurchase | 19,421 |
| | 19,421 |
| | 19,421 |
| | — |
| | — |
| Federal Home Loan Bank Term Advances | 51,000 |
| | 51,258 |
| | 41,000 |
| | 10,258 |
| | — |
| Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts | 20,000 |
| | 20,000 |
| | — |
| | 20,000 |
| | — |
| Accrued Interest Payable | 274 |
| | 274 |
| | 274 |
| | — |
| | — |
| | | | | | | | | | |
|