Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 17,828	$ 18,428
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of intangibles	2,292	2,444
Provision for loan losses	1,500	5,000
Deferred tax expense	1,204	415
Increase in cash surrender value of Bank-owned life insurance	(1,210)	(1,362)
Net amortization of premiums and discounts on securities	3,838	3,713
Accretion of net deferred loan fees	(1,291)	(832)
Amortization of premiums on purchased loans, net	324	427
Net increase in loans originated for sale	(10,446)	(9,355)
Proceeds from sales of loans originated for sale	10,824	9,800
Proceeds from sales of foreclosed assets	2,639	3,657
ESOP expense	627	585
Allocation of stock award shares	916	944
Allocation of stock options	71	89
Net gain on sale of loans	(378)	(445)
Net gain on securities transactions	(511)	(2,183)
Net gain on sale of premises and equipment		42
Net loss (gain) on sale of foreclosed assets	214	(25)
Decrease in accrued interest receivable	1,903	1,952
(Increase) decrease in other assets	(5,026)	2,060
Decrease in other liabilities	(6,475)	(2,917)
Net cash provided by operating activities	18,843	32,437
Cash flows from investing activities:
Proceeds from maturities, calls and paydowns of investment securities held to maturity	31,731	29,134
Purchases of investment securities held to maturity	(15,789)	(32,662)
Proceeds from sales of securities	7,919	47,131
Proceeds from maturities and paydowns of securities available for sale	106,313	118,432
Purchases of securities available for sale	(71,352)	(190,565)
Purchases of loans	(2,797)	(19,088)
Net (increase) decrease in loans	(4,568)	8,930
Proceeds from sales of premises and equipment		71
Purchases of premises and equipment	(1,165)	(982)
Net cash provided by (used in) by investing activities	50,292	(39,599)
Cash flows from financing activities:
Net (decrease) increase in deposits	(151,690)	38,277
Increase in mortgage escrow deposits	1,303	2,415
Purchase of treasury stock	(839)	(1,938)
Cash dividends paid to stockholders	(8,086)	(7,330)
Shares issued dividend reinvestment plan	301	2,475
Stock options exercised	18
Proceeds from long-term borrowings	20,000
Payments on long-term borrowings	(20,406)	(397)
Net increase (decrease) in short-term borrowings	51,148	(26,717)
Net cash (used in) provided by financing activities	(108,251)	6,785
Net decrease in cash and cash equivalents	(39,116)	(377)
Cash and cash equivalents at beginning of period	103,823	69,632
Cash and cash equivalents at end of period	64,707	69,255
Cash paid during the period for:
Interest on deposits and borrowings	9,508	12,147
Income taxes	5,002
Non cash investing activities:
Transfer of loans receivable to foreclosed assets	$ 2,676	$ 5,270