Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities:
Net income	$ 121,238	$ 113,265
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	23,883	14,404
Depreciation and amortization	24,975	23,952
Stock-based compensation expense	7,817	5,754
Excess tax benefits from stock-based compensation arrangements	(660)	(339)
Net amortization of premium on securities	2,576	4,733
Mortgage servicing rights fair value change, net	641	706
Originations and purchases of mortgage loans held-for-sale	(3,094,901)	(2,272,919)
Proceeds from sales of mortgage loans held-for-sale	3,182,623	2,299,103
Bank owned life insurance, net of claims	(1,683)	(2,039)
Increase in trading securities, net	(2,106)	(5,518)
Net (increase) decrease in brokerage customer receivables	(4,072)	4,329
Gains on mortgage loans sold	(83,437)	(55,160)
(Gains) losses on available-for-sale securities, net	(402)	522
Losses on sales of premises and equipment, net	512	664
Net (gains) losses on sales and fair value adjustments of other real estate owned	(585)	2,628
(Increase) decrease in accrued interest receivable and other assets, net	(110,632)	82,159
Decrease in accrued interest payable and other liabilities, net	(28,717)	(55,874)
Net Cash Provided by Operating Activities	37,070	160,370
Investing Activities:
Proceeds from maturities of available-for-sale securities	397,832	222,434
Proceeds from sales of available-for-sale securities	1,216,860	578,594
Purchases of available-for-sale securities	(1,584,282)	(944,281)
Redemption (purchase) of Federal Home Loan Bank and Federal Reserve Bank stock, net	1,274	(1,690)
Net cash (paid) received for acquisitions	(15,428)	228,946
Proceeds from sales of other real estate owned	34,936	73,940
Proceeds received from the FDIC related to reimbursements on covered assets	1,697	17,652
Net decrease (increase) in interest bearing deposits with banks	438,072	(124,796)
Net increase in loans	(1,311,797)	(1,011,889)
Redemption of bank owned life insurance	2,701	0
Purchases of premises and equipment, net	(29,375)	(30,982)
Net Cash Used for Investing Activities	(847,510)	(992,072)
Financing Activities:
Increase in deposit accounts	970,090	1,000,603
Increase (decrease) in other borrowings, net	38,644	(203,621)
Decrease in Federal Home Loan Bank advances, net	(293,360)	(70,000)
Proceeds from the issuance of preferred stock, net	120,842	0
Proceeds from the issuance of subordinated notes, net	0	139,090
Excess tax benefits from stock-based compensation arrangements	660	339
Issuance of common shares resulting from the exercise of stock options and the employee stock purchase plan	14,413	8,043
Common stock repurchases	(415)	(519)
Dividends paid	(20,486)	(18,681)
Net Cash Provided by Financing Activities	830,388	855,254
Net Increase in Cash and Cash Equivalents	19,948	23,552
Cash and Cash Equivalents at Beginning of Period	230,707	263,864
Cash and Cash Equivalents at End of Period	$ 250,655	$ 287,416