Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net income	$ 27,170	$ 25,801	$ 23,604
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	6,550	11,500	12,600
Depreciation, amortization and accretion, net	7,969	4,964	4,019
Deferred income tax expense (benefit)	570	(2,933)	(2,068)
Loss on sale of securities available for sale	5
Gains on sales of mortgage loans held for sale	(2,657)	(4,321)	(2,122)
Origination of mortgage loans held for sale	(149,745)	(241,128)	(126,306)
Proceeds from sale of mortgage loans held for sale	164,692	235,783	136,434
Bank owned life insurance income	(1,031)	(1,006)	(1,019)
(Increase) decrease in value of private investment fund		(637)	421
Proceeds from liquidation of private investment fund		2,846
Loss on other real estate owned	652	1,410	1,716
Loss on the disposal of equipment	51	190	382
Gain on acquisition	(449)
Stock compensation expense	1,940	1,481	1,165
Excess tax benefits from share-based compensation arrangements	(265)	(83)	(125)
Decrease in accrued interest receivable and other assets	736	769	3,533
Increase (decrease) in accrued interest payable and other liabilities	2,141	(19,840)	(7,805)
Net cash provided by operating activities	58,329	14,796	44,429
Investing activities
Purchases of securities available for sale	(443,969)	(488,390)	(404,514)
Proceeds from sale of securities available for sale	696
Proceeds from maturities of securities available for sale	406,385	452,447	300,620
Proceeds from maturities of securities held to maturity			20
Net increase in loans	(112,156)	(53,599)	(57,037)
Purchases of premises and equipment	(2,365)	(3,301)	(8,249)
Acquisition, net of cash acquired	8,963
Proceeds from disposal of equipment		3	7
Proceeds from sale of foreclosed assets	6,578	2,976	7,206
Net cash used in investing activities	(135,868)	(89,864)	(161,947)
Financing activities
Net increase in deposits	78,809	163,954	124,271
Net increase (decrease) in securities sold under agreements to repurchase and federal funds purchased	39,551	(27,702)	17,788
Net decrease in other short-term borrowings			(1,998)
Proceeds from Federal Home Loan Bank advances	12,510	31,462
Repayments of Federal Home Loan Bank advances	(10,063)	(60,011)	(11)
Repayments of subordinated debentures	(30,900)	(10,000)
Issuance of common stock for options and dividend reinvestment plan	2,435	961	705
Excess tax benefits from share-based compensation arrangements	265	83	125
Common stock repurchases	(331)	(205)	(167)
Cash dividends paid	(11,670)	(10,691)	(9,930)
Net cash provided by financing activities	80,606	87,851	130,783
Net increase in cash and cash equivalents	3,067	12,783	13,265
Cash and cash equivalents at beginning of year	67,703	54,920	41,655
Cash and cash equivalents at end of period	$ 70,770	$ 67,703	$ 54,920