Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Activities
Net income	$ 52,531	$ 53,963
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	9,377	4,397
Depreciation, amortization, and accretion, net	13,785	13,799
Deferred income tax expense	28,601	28,718
Decrease (increase) in trading account assets	296	(6,139)
Originations of mortgage loans held for sale	(138,695)	(207,530)
Proceeds from sales of mortgage loans held for sale	138,677	184,712
Gain on sales of mortgage loans held for sale, net	(3,424)	(4,202)
(Increase) in other assets	(39,363)	(6,103)
Increase (decrease) in other liabilities	17,341	(30,818)
Investment securities gains, net	(67)	(725)
Losses and write-downs on other real estate, net	2,098	7,275
Losses and write-downs on other assets held for sale, net	1,270	0
Loss on early extinguishment of debt	4,735	0
Share-based compensation expense	3,337	3,234
Net cash provided by operating activities	90,499	40,581
Investing Activities
Net (increase) decrease in interest earning deposits with banks	(4,299)	4,939
Net increase in federal funds sold and securities purchased under resale agreements	(6,481)	(7,661)
Net increase in interest bearing funds with Federal Reserve Bank	(78,640)	(542,524)
Proceeds from maturities and principal collections of investment securities available for sale	168,039	155,005
Proceeds from sales of investment securities available for sale	243,609	32,419
Purchases of investment securities available for sale	(363,788)	(265,707)
Proceeds from sales of loans and principal repayments on other loans held for sale	4,259	12,507
Proceeds from sales of loans and principal repayments on other loans held for sale	10,798	8,785
Net increase in loans	(344,159)	(36,336)
Net increase in premises and equipment	(7,830)	(5,221)
Proceeds from sales of other assets held for sale	0	351
Net cash used in investing activities	(378,492)	(643,443)
Financing Activities
Net increase in demand and savings deposits	110,837	411,991
Net increase in certificates of deposit	96,212	164,184
Net increase (decrease) in federal funds purchased and securities sold under repurchase agreements	26,954	(1,593)
Repayments on long-term debt	(830,067)	(375,039)
Proceeds from issuance of long-term debt	1,000,000	425,000
Dividends paid to common shareholders	(15,069)	(13,434)
Dividends paid to preferred shareholders	(2,559)	(2,559)
Stock options exercised	456	1,692
Repurchases of common stock	(110,985)	(59,113)
Restricted stock activity	(2,818)	(4,418)
Net cash provided by financing activities	272,961	546,711
Decrease in cash and cash equivalents	(15,032)	(56,151)
Cash and cash equivalents at beginning of period	367,092	485,489
Cash and cash equivalents at end of period	352,060	429,338
Supplemental Cash Flow Information
Income tax payments (refunds), net	(656)	338
Interest paid	32,141	27,875
Non-cash Activities
Premises and equipment transferred to other assets held for sale	4,828	0
Loans foreclosed and transferred to other real estate	4,328	5,378
Loans transferred to other loans held for sale at fair value	$ 3,834	$ 10,100