Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Time certificates of deposit least amount	$ 100,000	$ 100,000
Securities held to maturity, fair value	$ 379,699,000	$ 346,455,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000us-gaap_PreferredStockSharesAuthorized	1,000,000us-gaap_PreferredStockSharesAuthorized
Preferred stock, shares outstanding	0us-gaap_PreferredStockSharesOutstanding	0us-gaap_PreferredStockSharesOutstanding
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000us-gaap_CommonStockSharesAuthorized	75,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	23,998,738us-gaap_CommonStockSharesIssued	23,805,984us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	23,998,738us-gaap_CommonStockSharesOutstanding	23,805,984us-gaap_CommonStockSharesOutstanding
Common stock, unvested restricted Stock awards	254,500	268,290
Shares held in rabbit trust at cost	176,849indb_SharesHeldInRabbiTrustAtCost	178,765indb_SharesHeldInRabbiTrustAtCost

Shares Held in Rabbi Trust

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Face amount or stated value per share of common stock.

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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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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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

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The aggregate of all domestic and foreign interest-bearing deposit liabilities.

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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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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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