Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 16,693	$ 13,574	$ 10,160
Adjustments to reconcile net income to net cash provided by operating activities:
Mortgage loans originated for sale	(22,664)		(374)
Proceeds from mortgage loans sold	19,697		379
Gain on sales of mortgage loans held for sale	(422)		(5)
Gain on sale of loans	(238)
Gain on sale of fixed assets		(7)	(70)
Net gains on sales of securities	(1,940)	(1,851)	(2,734)
Provision for loan losses	4,550	5,575	6,625
Deferred tax benefit	(953)	(1,546)	(2,294)
Net depreciation and amortization	5,558	4,955	6,035
Decrease (increase) in accrued interest receivable	579	(795)	917
Decrease (increase) in prepaid FDIC assessments	1,794	2,629	(8,757)
Loss (gain) on sales of other real estate owned	8	(127)
Writedown of other real estate owned	117
Increase in other assets	(4,456)	(1,417)	(3,822)
Increase (decrease) in other liabilities	503	(849)	2,003
Net cash provided by operating activities	18,826	20,141	8,063
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of short-term investments	121,106	131,762	221,628
Purchase of short-term investments	(25,539)	(227,162)	(196,332)
Proceeds from calls/maturities of securities available-for-sale	722,403	610,975	327,615
Proceeds from sales of securities available-for-sale	75,615	41,251	94,142
Purchase of securities available-for-sale	(1,140,194)	(914,944)	(566,680)
Proceeds from calls/maturities of securities held-to-maturity	119,315	154,445	94,069
Purchase of securities held-to-maturity	(68,863)	(167,442)	(128,373)
Proceeds from sales of loans	4,000
Net increase in loans	(82,793)	(33,315)	(46,385)
Proceeds from sales of other real estate owned	802	555
Proceeds from sales of fixed assets		13	100
Capital expenditures	(2,692)	(2,281)	(1,257)
Net cash used in investing activities	(276,840)	(406,143)	(201,473)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase (decrease) in time deposit accounts	16,241	124,622	(34,234)
Net increase in demand, savings, money market and NOW deposits	206,320	75,414	470,694
Net payments for the repurchase of stock			(107)
Net proceeds from the exercise of stock options	52	150
Cash dividends	(2,180)	(2,173)	(2,170)
Net increase (decrease) in securities sold under agreements to repurchase	34,770	(10,195)	6,235
Net increase (decrease) in other borrowed funds	22,025	(11,906)	(4,534)
Net cash provided by financing activities	277,228	175,912	435,884
Net increase (decrease) in cash and cash equivalents	19,214	(210,090)	242,474
Cash and cash equivalents at beginning of year	188,552	398,642	156,168
Cash and cash equivalents at end of year	207,766	188,552	398,642
Cash paid during the year for:
Interest	22,799	24,930	32,202
Income taxes	3,109	3,580	2,858
Change in unrealized gains on securities available-for-sale, net of taxes	4,726	(536)	4,421
Pension liability adjustment, net of taxes	(3,667)	1,259	(77)
Transfer of loans to other real estate owned	$ 2,110	$ 428