Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities
Net income	$ 19,250,000	$ 20,338,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	2,708,000	3,271,000
Depreciation and amortization	3,343,000	2,618,000
Stock-based compensation expense	355,000	593,000
Decrease in interest receivable	58,000	356,000
Amortization of intangible assets	433,000	433,000
Net (increase) decrease in trading assets	(15,000)	142,000
Net investment securities gains	(1,098,000)	(197,000)
Other-than-temporary impairment of securities	39,000	88,000
Increase in other real estate owned valuation allowance and loss on disposition	465,000	188,000
Originations of mortgage loans held for sale	(12,775,000)	(11,848,000)
Proceeds from the sale of mortgage loans	19,104,000	16,817,000
Gain on sale of mortgage loans	(268,000)	(203,000)
Decrease in prepaid FDIC assessment	875,000	1,067,000
Increase in other assets	(62,000)	(5,660,000)
Increase in other liabilities	474,000	3,238,000
Net cash provided by operating activities	32,886,000	31,241,000
Investing Activities
Proceeds from maturities of securities held to maturity		251,000
Proceeds from sales and maturities of securities available for sale	154,708,000	133,416,000
Purchase of securities available for sale	(267,533,000)	(125,358,000)
Net (increase) decrease in loans	(30,544,000)	7,231,000
Proceeds from sale of FHLB stock	928,000
Proceeds from the sale of other real estate owned	1,665,000	1,638,000
Proceeds from bank-owned life insurance		370,000
Proceeds from previously charged-off loans	530,000	865,000
Purchase of premises and equipment	(2,662,000)	(722,000)
Net cash (used) provided by investing activities	(142,908,000)	17,691,000
Financing Activities
Net increase in deposits	97,953,000	125,449,000
Proceeds from Federal Home Loan Bank long-term advances		190,000,000
Repayments on Federal Home Loan Bank long-term advances	(10,341,000)	(277,265,000)
Net change in short-term Federal Home Loan Bank borrowings	45,000,000	(37,275,000)
Net (decrease) increase in other borrowed funds	(4,888,000)	14,335,000
Common stock repurchase	(2,097,000)	(272,000)
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings and tax benefit	(241,000)	118,000
Cash dividends paid on common stock	(5,756,000)	(5,765,000)
Net cash provided by financing activities	119,630,000	9,325,000
Net increase in cash and cash equivalents	9,608,000	58,257,000
Cash and cash equivalents at beginning of year	39,325,000	31,009,000
Cash and cash equivalents at end of period	48,933,000	89,266,000
Supplemental information
Interest paid	13,402,000	18,433,000
Income taxes paid	4,560,000	8,340,000
Transfer from loans to other real estate owned	$ 1,044,000	$ 1,198,000