Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
OPERATING ACTIVITIES:
Net income	$ 119,339	$ 94,149	$ 64,753
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion, net	9,875	4,406	10,683
Provision for loan losses	15,043	17,966	19,714
Net gain on sale of mortgage loans held for sale	(9,698)	(4,091)	(5,989)
Origination of mortgage loans held for sale	(243,066)	(134,059)	(288,893)
Proceeds from sale of mortgage loans held for sale	246,542	148,986	285,099
Net realized impairment of mortgage servicing rights	142	203
Net realized (gain) loss on sales, calls and impairment of securities	(56)	(2,006)	221
Net gain on sale of other real estate owned	(416)	(444)	(203)
Writedowns of other real estate owned	1,719	917	1,127
Deferred director compensation expense - Company Stock	227	171	151
Stock based compensation expense	842	277	567
Bargain purchase gains on acquisitions	(55,438)
Gain on sale of banking center		(2,856)
Net change in other assets and liabilities:
Accrued interest receivable	434	(262)	577
Accrued interest payable	(321)	(646)	(511)
Other assets	6,289	1,665	7,926
Other liabilities	(1,543)	(772)	(5,988)
Net cash provided by operating activities	89,914	123,604	89,234
INVESTING ACTIVITIES:
Net cash proceeds received in FDIC-assisted transactions	921,247
Purchases of securities available for sale	(61,717)	(598,495)	(611,521)
Purchases of securities to be held to maturity	(23,114)	(500)	(685)
Purchases of Federal Home Loan Bank stock		(46)	(26)
Proceeds from calls, maturities and paydowns of securities available for sale	287,773	310,331	524,423
Proceeds from calls, maturities and paydowns of securities to be held to maturity	5,341	5,402	18,669
Proceeds from sales of securities available for sale	38,724	161,652
Proceeds from sales of Federal Home Loan Bank stock	469	278	62
Proceeds from sales of other real estate owned	25,326	11,844	9,474
Purchase of commercial real estate loans		(32,650)
Net change in loans	(198,520)	(117,864)	55,545
Net purchases of premises and equipment	(3,888)	(3,727)	(4,268)
Sale of banking center		(15,388)
Net cash provided by/(used in) investing activities	991,641	(279,163)	(8,327)
Financing activities:
Net change in deposits	(894,756)	(536,792)	(299,789)
Net change in securities sold under agreements to repurchase and other short-term borrowings	20,653	(88,433)	19,666
Payments of Federal Home Loan Bank advances	(590,095)	(75,247)	(117,730)
Proceeds from Federal Home Loan Bank advances	195,000	445,000	45,000
Repurchase of Common Stock	(1,668)	(492)	(390)
Net proceeds from Common Stock options exercised	147	438	1,884
Cash dividends paid	(36,116)	(12,315)	(11,356)
Net cash used in financing activities	(1,306,835)	(267,841)	(362,715)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(225,280)	(423,400)	(281,808)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	362,971	786,371	1,068,179
CASH AND CASH EQUIVALENTS AT END OF PERIOD	137,691	362,971	786,371
Cash paid during the year for:
Interest	23,125	30,908	37,172
Income taxes	53,763	48,947	28,674
SUPPLEMENTAL NONCASH DISCLOSURES:
Transfers from loans to real estate acquired in settlement of loans	20,610	11,300	17,802
Loans provided for sales of other real estate owned	$ 1,554	$ 3,119	$ 2,294