Fair Value Measurements (Details) (USD $)	Mar. 31, 2015 item	Dec. 31, 2014
Fair Value Measurements
Investment securities available-for-sale	$ 314,260,000us-gaap_AvailableForSaleSecurities	$ 339,131,000us-gaap_AvailableForSaleSecurities
Investment securities - trading	5,453,000us-gaap_TradingSecurities	5,067,000us-gaap_TradingSecurities
Investment securities held-to-maturity	3,425,000	3,334,000
Number of pooled trust preferred securities	3
Total par value	4,000,000
Transfer in and out between level 1, level 2 and level 3	0
U.S. government-sponsored agencies
Fair Value Measurements
Investment securities available-for-sale	54,605,000	74,153,000
Mortgage-backed securities
Fair Value Measurements
Investment securities available-for-sale	122,814,000	125,481,000
Investment securities held-to-maturity	15,000	19,000
Municipal securities
Fair Value Measurements
Investment securities available-for-sale	134,461,000	137,122,000
Pooled trust preferred and corporate securities
Fair Value Measurements
Investment securities available-for-sale	2,380,000	2,375,000
Investment securities held-to-maturity	3,410,000	3,315,000
Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Loans receivable - evaluated for impairment	301,000	301,000
Significant Unobservable Inputs (Level 3)
Fair Value Measurements
Loans receivable - evaluated for impairment	2,602,350,000	2,545,619,000
Number of relationships	4
Significant Unobservable Inputs (Level 3) \| Loans secured primarily by commercial real estate
Fair Value Measurements
Loans receivable - evaluated for impairment	273,000
Number of relationships	1
Significant Unobservable Inputs (Level 3) \| Loans primarily secured by business assets
Fair Value Measurements
Loans receivable - evaluated for impairment	1,200,000
Number of relationships	3
Recurring Fair Value Measurements \| Balance
Fair Value Measurements
Investment securities available-for-sale	314,260,000	339,131,000
Investment securities - trading	5,453,000	5,067,000
Bank-owned life insurance	32,664,000	32,546,000
Recurring Fair Value Measurements \| Balance \| Rate Lock and Forward Loan Sales Commitments
Fair Value Measurements
Derivative asset	21,380,000	14,488,000
Derivative liability	4,933,000	2,725,000
Recurring Fair Value Measurements \| Balance \| Rate Lock Commitments
Fair Value Measurements
Derivative asset	2,179,000	562,000
Derivative liability	123,000	33,000
Recurring Fair Value Measurements \| Balance \| U.S. government-sponsored agencies
Fair Value Measurements
Investment securities available-for-sale	54,605,000	74,153,000
Recurring Fair Value Measurements \| Balance \| Mortgage-backed securities
Fair Value Measurements
Investment securities available-for-sale	122,814,000	125,481,000
Recurring Fair Value Measurements \| Balance \| Municipal securities
Fair Value Measurements
Investment securities available-for-sale	134,461,000	137,122,000
Recurring Fair Value Measurements \| Balance \| Pooled trust preferred and corporate securities
Fair Value Measurements
Investment securities available-for-sale	2,380,000	2,375,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Investment securities available-for-sale	314,260,000	339,131,000
Investment securities - trading	5,453,000	5,067,000
Bank-owned life insurance	32,664,000	32,546,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| Rate Lock and Forward Loan Sales Commitments
Fair Value Measurements
Derivative asset	21,380,000	14,488,000
Derivative liability	4,933,000	2,725,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| Rate Lock Commitments
Fair Value Measurements
Derivative asset	2,179,000	562,000
Derivative liability	123,000	33,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| U.S. government-sponsored agencies
Fair Value Measurements
Investment securities available-for-sale	54,605,000	74,153,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| Mortgage-backed securities
Fair Value Measurements
Investment securities available-for-sale	122,814,000	125,481,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| Municipal securities
Fair Value Measurements
Investment securities available-for-sale	134,461,000	137,122,000
Recurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2) \| Pooled trust preferred and corporate securities
Fair Value Measurements
Investment securities available-for-sale	2,380,000	2,375,000
Nonrecurring Fair Value Measurements \| Balance
Fair Value Measurements
Loans receivable - evaluated for impairment	1,745,000	1,878,000
Nonrecurring Fair Value Measurements \| Balance \| Pooled trust preferred and corporate securities
Fair Value Measurements
Investment securities held-to-maturity	3,410,000	3,315,000
Nonrecurring Fair Value Measurements \| Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Loans receivable - evaluated for impairment	301,000	301,000
Nonrecurring Fair Value Measurements \| Significant Unobservable Inputs (Level 3)
Fair Value Measurements
Loans receivable - evaluated for impairment	1,444,000	1,577,000
Nonrecurring Fair Value Measurements \| Significant Unobservable Inputs (Level 3) \| Pooled trust preferred and corporate securities
Fair Value Measurements
Investment securities held-to-maturity	$ 3,410,000	$ 3,315,000

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Amount of transfer in and out of level 1, level 2 and level 3.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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