Balance Sheet Parenthetical (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Held-to-maturity Securities, at Fair Value	$ 308,566	$ 302,305
Preferred Stock, Par Value	$ 5	$ 5
Preferred Stock, Shares Authorized	1,000,000us-gaap_PreferredStockSharesAuthorized	1,000,000us-gaap_PreferredStockSharesAuthorized
Common Stock, Par Value	$ 1	$ 1
Common Stock, Shares Authorized	20,000,000us-gaap_CommonStockSharesAuthorized	20,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, Shares Issued	17,079,376us-gaap_CommonStockSharesIssued	16,744,486us-gaap_CommonStockSharesIssued
Unallocated ESOP Shares - Shares	71,748arow_UnallocatedEsopShares	87,641arow_UnallocatedEsopShares
Treasury Stock, Shares	4,386,022us-gaap_TreasuryStockShares	4,296,723us-gaap_TreasuryStockShares

Unallocated ESOP Shares

No definition available.

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- Definition

Face amount or stated value per share of common stock.

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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- Definition

Fair value of investments in debt securities classified as held-to-maturity.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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