CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATING ACTIVITIES:
Net income	$ 54,165	$ 46,555	$ 64,882
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	8,064	7,457	7,788
Deferred income and expense, net of amortization	1,541	3,200	2,864
Amortization of core deposit intangibles	1,990	1,941	2,092
Gain on sale of securities, net	(42)	(1,022)	(51)
Other-than-temporary impairment (recovery) loss	0	(409)	409
Net change in valuation of financial instruments carried at fair value	(1,374)	2,278	16,515
Purchases of securities—trading	(2,387)	(32,413)	(5,408)
Proceeds from sales of securities—trading	2,387	34,308	5,073
Principal repayments and maturities of securities—trading	27,709	6,509	15,880
Bargain purchase gain on acquisition	(9,079)	0	0
Decrease (increase) in deferred taxes	2,871	7,528	(35,007)
Increase (decrease) in current taxes payable	11,771	(10,818)	1,089
Equity-based compensation	2,269	1,049	440
Increase in cash surrender value of BOLI	(1,788)	(1,999)	(2,554)
Gain on sale of loans, net of capitalized servicing rights	(6,080)	(6,498)	(10,154)
Gain on disposal of real estate held for sale and property and equipment	(1,076)	(2,521)	(4,614)
Provision for losses on loans and real estate held for sale	36	785	18,178
Origination of loans held for sale	(361,859)	(427,542)	(503,492)
Proceeds from sales of loans held for sale	367,888	443,225	504,734
Net change in:
Other assets	(2,310)	19,426	(818)
Other liabilities	3,370	4,327	3,569
Net cash provided from operating activities	98,066	95,366	81,415
INVESTING ACTIVITIES:
Purchases of securities—available-for-sale	(58,705)	(197,911)	(413,482)
Principal repayments and maturities of securities—available-for-sale	62,520	84,424	389,414
Proceeds from sales of securities—available-for-sale	56,267	103,274	13,282
Purchases of securities—held-to-maturity	(38,961)	(26,221)	(23,007)
Principal repayments and maturities of securities—held-to-maturity	9,194	9,788	11,806
Loan originations, net of principal repayments	(144,152)	(167,085)	45,979
Purchases of loans and participating interest in loans	(194,381)	(48,725)	(18,477)
Proceeds from sales of other loans	11,277	19,305	9,851
Net cash received from acquisitions	127,557	6,809	0
Purchases of property and equipment, net of sales	(5,935)	(8,211)	(5,613)
Proceeds from sale of real estate held for sale, net	4,923	16,944	40,965
Proceeds from FHLB stock repurchase program	8,354	1,315	666
Other	(2,025)	(127)	1,095
Net cash provided from (used by) investing activities	(164,067)	(206,421)	52,479
FINANCING ACTIVITIES
Increase in deposits, net	68,938	51,417	82,150
Advances, net of (repayments) of FHLB borrowings	4,992	16,993	(6)
Increase (decrease) in other borrowings, net	(5,871)	6,423	(75,495)
Cash dividends paid	(13,462)	(7,799)	(6,470)
Cash proceeds from issuance of stock for stockholder reinvestment plan	127	72	36,317
Redemption of preferred stock	0	0	(121,528)
Net cash provided from (used by) financing activities	54,724	67,106	(85,032)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	(11,277)	(43,949)	48,862
CASH AND DUE FROM BANKS, BEGINNING OF YEAR	137,349	181,298	132,436
CASH AND DUE FROM BANKS, END OF YEAR	126,072	137,349	181,298
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid in cash	10,929	13,362	20,712
Taxes paid in cash	13,047	22,828	9,631
NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Loans, net of discounts, specific loss allowances and unearned income, transferred to real estate owned and other repossessed assets	3,493	3,448	14,070
ACQUISITIONS (Note 4):
Assets acquired	221,206	8,710	0
Liabilities assumed	$ 212,127	$ 8,710	$ 0