Consolidated Statements Of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating Activities:
Net income	$ 39,052	$ 34,500
Adjustments to reconcile net income to net cash (used for) provided by operating activities
Provision for credit losses	6,079	1,880
Depreciation and amortization	7,895	7,753
Stock-based compensation expense	2,271	1,681
Tax (expense) benefit from stock-based compensation arrangements	(623)	3
Excess tax benefits from stock-based compensation arrangements	(471)	(156)
Net amortization of premium on securities	845	233
Mortgage servicing rights fair value change, net	514	253
Originations and purchases of mortgage loans held-for-sale	(941,651)	(527,272)
Proceeds from sales of mortgage loans held-for-sale	867,194	658,588
Increase in trading securities, net	(6,605)	(571)
Net (increase) decrease in brokerage customer receivables	(1,066)	4,069
Gains on mortgage loans sold	(20,608)	(12,220)
(Gains) losses on available-for-sale securities, net	(524)	33
Losses on sales of premises and equipment, net	81	795
Net (gains) losses on sales and fair value adjustments of other real estate owned	(549)	2,460
(Increase) decrease in accrued interest receivable and other assets, net	(21,291)	27,584
Decrease in accrued interest payable and other liabilities, net	(48,874)	(37,348)
Net Cash (Used for) Provided by Operating Activities	(118,331)	162,265
Investing Activities:
Proceeds from maturities of available-for-sale securities	122,163	98,007
Proceeds from sales of available-for-sale securities	635,532	14,800
Purchases of available-for-sale securities	(629,008)	(349,979)
Net cash received for acquisitions	12,004	0
Proceeds from sales of other real estate owned	11,733	20,362
(Payments provided to) proceeds received from the FDIC related to reimbursements on covered assets	(2,056)	9,669
Net decrease (increase) in interest bearing deposits with banks	300,706	(45,390)
Net increase in loans	(407,522)	(227,040)
Purchases of premises and equipment, net	(5,902)	(7,596)
Net Cash Provided by (Used for) Investing Activities	37,650	(487,167)
Financing Activities:
Increase in deposit accounts	486,960	460,551
Decrease in other borrowings, net	(20,327)	(24,018)
Decrease in Federal Home Loan Bank advances, net	(321,565)	(30,000)
Excess tax benefits from stock-based compensation arrangements	471	156
Issuance of common shares resulting from exercise of stock options, employee stock purchase plan and conversion of common stock warrants	2,489	3,668
Common stock repurchases	(399)	(380)
Dividends paid	(6,783)	(6,201)
Net Cash Provided by Financing Activities	140,846	403,776
Net Increase in Cash and Cash Equivalents	60,165	78,874
Cash and Cash Equivalents at Beginning of Period	230,707	263,864
Cash and Cash Equivalents at End of Period	$ 290,872	$ 342,738