CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net income	$ 25,110	$ 16,624	$ 8,918
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	5,742	4,431	4,026
Provision for loan and lease losses	29,500	22,438	21,498
Net amortization of investment securities discounts/premiums	6,811	2,090	669
Stock-based compensation expense	3,157	2,595	1,800
Loans originated for resale	(276,562)	(28,876)	(458)
Sale of loans originated for resale	268,019	19,420	462
Gain on sales of loans originated for resale	(17,225)	(1,885)	(4)
Deferred income tax expense	(2,412)	(2,899)	(1,961)
Gain on sales of fixed assets	(24)	(31)	(25)
Other than temporary impairment on securities held-to-maturity	20	202	75
Losses on sale and write downs of other real estate owned	1,461	2,508	555
Gain on sales of investment securities	(1,889)	(661)	(759)
Decrease (increase) in accrued interest receivable	(3,274)	(1,381)	402
Decrease in interest payable	(24)	(20)	(1)
(Increase) decrease in other assets	(4,687)	(9,272)	1,125
Increase in other liabilities	15,307	7,759	1,318
Net cash provided by operating activities	49,030	33,042	37,640
Investing activities
Purchase of investment securities available-for-sale	(884,050)	(473,828)	(345,809)
Purchase of investment securities held-to-maturity	(52,899)
Proceeds from redemptions and prepayments of securities held-to-maturity	963	2,076	4,000
Proceeds from redemptions and prepayments of securities available-for-sale	335,277	180,457	135,621
Proceeds from sale of other real estate owned	2,373	5,536	894
Net increase in loans	(138,632)	(181,872)	(148,365)
Proceeds from sale of fixed assets	136	357	97
Purchases of premises and equipment	(9,098)	(5,098)	(2,106)
Net cash used in investing activities	(745,930)	(472,372)	(355,668)
Financing activities
Net increase in deposits	959,768	630,670	658,454
Net increase (decrease) in securities sold under agreements to repurchase	2,673	(14,629)	18,794
Repayment of short-term borrowings			(136,000)
Proceeds from issuance of common stock	1,629	41,713	54,501
Purchase of treasury stock			(866)
Proceeds from the exercise of options	1,653	454
Excess tax benefit from share-based payment arrangements	1,020	40
Net cash provided by financing activities	966,743	658,248	594,883
Effect of exchange rate changes on cash and cash equivalents	7
Net increase in cash and cash equivalents	269,850	218,918	276,855
Cash and cash equivalents, beginning of year	968,092	749,174	472,319
Cash and cash equivalents, end of year	1,237,942	968,092	749,174
Supplemental disclosure:
Interest paid	10,792	11,431	12,037
Taxes paid	17,602	11,049	6,139
Transfers of loans to other real estate owned	25,888	4,880	6,739
Transfers of loans to held for sale	$ 32,795
Common stock shares issued, cashless transaction	140,228