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	$ 111,196	$ 77,575	$ 63,329
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	76,436	102,638	124,664
Depreciation and amortization	24,676	19,469	18,165
Deferred income tax benefit	(23,315)	(639)	(15,972)
Stock-based compensation expense	9,072	5,692	4,640
Tax benefit from stock-based compensation arrangements	1,392	129	881
Excess tax benefits from stock-based compensation arrangements	(841)	(306)	(1,354)
Net (accretion) amortization of premium on securities	(1,034)	4,434	8,910
Mortgage servicing rights fair value change, net	4,101	4,673	2,977
Originations and purchases of mortgage loans held-for-sale	(3,866,012)	(2,545,385)	(3,746,127)
Proceeds from sales of mortgage loans held-for-sale	3,865,863	2,638,162	3,723,773
Bank owned life insurance income, net of claims	(2,920)	(2,569)	(2,404)
Decrease in trading securities, net	1,907	2,389	28,895
Net increase in brokerage customer receivables	3,061	(3,376)	(3,678)
Gain on mortgage loans sold	(91,527)	(41,854)	(73,378)
Gains on available-for-sale securities, net	(4,895)	(1,792)	(9,832)
Gain on bargain purchases, net	(7,503)	(37,974)	(44,231)
Loss on sales of premises and equipment, net	333	29	17
Net loss on sales and fair value adjustments of other real estate owned	15,316	20,110	13,546
Decrease in accrued interest receivable and other assets, net	15,605	12,582	46,541
Increase (decrease) in accrued interest payable and other liabilities, net	137,743	(9,720)	(15,349)
Net Cash (Used for) Provided by Operating Activities	268,654	244,267	124,013
Investing Activities:
Proceeds from maturities of available-for-sale securities	588,281	1,483,986	1,032,581
Proceeds from sales of available-for-sale securities	2,399,035	1,265,046	710,290
Purchases of available-for-sale securities	(2,570,373)	(3,087,864)	(2,016,636)
Net cash received for acquisitions	64,351	91,571	62,189
Proceeds from sales of other real estate owned	88,633	59,076	64,431
Proceeds received from the FDIC related to reimbursements on covered assets	169,689	92,595	44,091
Net (increase) decrease in interest-bearing deposits with banks	(212,564)	140,684	366,099
Net increase in loans	(948,601)	(802,926)	(733,376)
Purchases of premises and equipment, net	(74,326)	(79,132)	(30,510)
Net Cash Used for Investing Activities	(495,875)	(836,964)	(500,841)
Financing Activities:
Increase in deposit accounts	1,251,792	385,335	197,614
(Decrease) increase in other borrowings, net	(306,786)	226,050	13,173
Decrease in Federal Home Loan Bank advances, net	(70,000)	0	(36,735)
Repayment of subordinated note	(20,000)	(15,000)	(10,000)
Payoff of secured borrowing	(600,000)	0	0
Excess tax benefits from stock-based compensation arrangements	841	306	1,354
Redemption of Series B preferred stock	0	0	(250,000)
Net proceeds from issuance of Series C preferred stock	122,690	0	0
Issuance of prepaid common stock purchase contracts	0	0	179,316
Issuance of common stock, net of issuance costs	0	0	315,108
Issuance of common shares resulting from exercise of stock options, employee stock purchase plan and conversion of common stock warrants	14,891	3,586	3,956
Common stock repurchases	(7,726)	(112)	(218)
Dividends paid	(13,157)	(10,344)	(22,776)
Net Cash Provided by Financing Activities	372,545	589,821	390,792
Net Increase (Decrease) in Cash and Cash Equivalents	145,324	(2,876)	13,964
Cash and Cash Equivalents at Beginning of Period	169,704	172,580	158,616
Cash and Cash Equivalents at End of Period	315,028	169,704	172,580
Cash paid during the year for:
Interest	109,173	146,982	177,422
Income taxes, net	82,067	57,474	34,730
Acquisitions:
Fair value of assets acquired, at the acquisition date	1,158,925	1,257,085	673,277
Value ascribed to goodwill and other intangible assets	42,588	37,198	1,590
Fair value of liabilities assumed	1,160,084	1,220,189	730,522
Non-cash activities
Transfer to other real estate owned from loans	30,651	59,669	68,663
Common stock issued for acquisitions	$ 14,560	$ 27,091	$ 0