Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating Activities:
Net income	$ 99,152	$ 82,883
Adjustments to reconcile net income to net cash used for operating activities
Provision for credit losses	17,163	15,561
Depreciation, amortization and accretion, net	27,296	17,908
Stock-based compensation expense	4,752	5,286
Excess tax benefits from stock-based compensation arrangements	(267)	(476)
Net amortization of premium on securities	1,840	205
Accretion of discount on loans	(15,849)	(15,887)
Mortgage servicing rights fair value change, net	(4,291)	258
Originations and purchases of mortgage loans held-for-sale	(1,948,890)	(2,121,237)
Proceeds from sales of mortgage loans held-for-sale	1,825,686	2,034,173
Bank owned life insurance, net of claims	(1,729)	(1,470)
Increase in trading securities, net	(3,165)	(391)
Net decrease (increase) in brokerage customer receivables	765	(5,532)
Gains on mortgage loans sold	(43,014)	(58,929)
Gains on investment securities, net	(2,765)	(500)
Gains on early extinguishment of debt	(4,305)	0
Losses on sales of premises and equipment, net	3	403
Net losses on sales and fair value adjustments of other real estate owned	322	430
Increase in accrued interest receivable and other assets, net	(116,118)	(42,642)
Increase in accrued interest payable and other liabilities, net	70,756	17,757
Net Cash Used for Operating Activities	(92,658)	(72,200)
Investing Activities:
Proceeds from maturities of available-for-sale securities	529,463	335,286
Proceeds from maturities of held-to-maturity securities	319	0
Proceeds from sales and calls of available-for-sale securities	1,071,996	1,134,033
Proceeds from calls of held-to-maturity securities	281,981	0
Purchases of available-for-sale securities	(1,526,467)	(1,353,356)
Purchases of held-to-maturity securities	(350,078)	0
(Purchase) redemption of Federal Home Loan Bank and Federal Reserve Bank stock, net	(19,738)	1,764
Net cash (paid) received for acquisitions	(18,133)	12,004
Proceeds from sales of other real estate owned	19,455	24,444
Proceeds received from the FDIC related to reimbursements on covered assets	420	150
Net (increase) decrease in interest bearing deposits with banks	(81,250)	406,784
Net increase in loans	(942,958)	(949,907)
Redemption of bank owned life insurance	659	2,701
Purchases of premises and equipment, net	(24,235)	(25,478)
Net Cash Used for Investing Activities	(1,058,566)	(411,575)
Financing Activities:
Increase in deposit accounts	1,302,188	630,785
(Decrease) increase in other borrowings, net	(13,249)	54,645
Decrease in Federal Home Loan Bank advances, net	(271,025)	(293,584)
Proceeds from the issuance of common stock, net	152,823	0
Proceeds from the issuance of preferred stock, net	0	121,151
Redemption of junior subordinated debentures, net	(10,695)	0
Redemption of junior subordinated debentures, net	267	476
Issuance of common shares resulting from the exercise of stock options and the employee stock purchase plan	5,766	5,812
Common stock repurchases	(172)	(415)
Dividends paid	(18,899)	(13,593)
Net Cash Provided by Financing Activities	1,147,004	505,277
Net (Decrease) Increase in Cash and Cash Equivalents	(4,220)	21,502
Cash and Cash Equivalents at Beginning of Period	275,795	230,707
Cash and Cash Equivalents at End of Period	$ 271,575	$ 252,209