Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net income	$ 167,684	$ 142,077
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	13,990	25,638
Depreciation, amortization, and accretion, net	42,725	39,524
Deferred income tax expense	93,198	74,940
Decrease (increase) in trading account assets	8,019	(6,592)
Originations of mortgage loans held for sale	(656,987)	(579,139)
Proceeds from sales of mortgage loans held for sale	658,787	561,796
Gain on sales of mortgage loans held for sale, net	(12,531)	(8,971)
(Increase) decrease in other assets	(12,534)	816
(Decrease) increase in other liabilities	(11,679)	20,131
Investment securities gains, net	(2,710)	(1,331)
Losses and write-downs on other real estate, net	14,864	16,734
Share-based compensation expense	9,462	7,453
Write-downs on other assets held for sale	1,043	7,608
Gain on sale of Memphis branches, net	0	(5,789)
Net cash provided by operating activities	313,331	294,895
Investing Activities
Net cash used in dispositions	0	(90,571)
Net (increase) decrease in interest earning deposits with banks	(9,360)	10,713
Net decrease in federal funds sold and securities purchased under resale agreements	3,378	10,057
Net increase in interest bearing funds with Federal Reserve Bank	(116,278)	(105,918)
Proceeds from maturities and principal collections of investment securities available for sale	517,077	417,704
Proceeds from sales of investment securities available for sale	82,156	20,815
Purchases of investment securities available for sale	(1,048,048)	(277,375)
Proceeds from sales of loans and principal repayments on other loans held for sale	28,045	44,771
Proceeds from sale of other real estate	30,124	49,754
Net increase in loans	(839,971)	(754,930)
Purchases of BOLI policies	(45,000)	0
Net increase in premises and equipment	(21,667)	(31,221)
Proceeds from sale of other assets held for sale	2,304	507
Net cash used in investing activities	(1,417,240)	(705,694)
Financing Activities
Net increase in demand and savings deposits	1,500,506	8,677
Net (decrease) increase in certificates of deposit	(254,793)	295,687
Net increase (decrease) in federal funds purchased and securities sold under repurchase agreements	8,559	(40,972)
Principal repayments on long-term debt	(525,000)	(800,667)
Proceeds from issuance of long-term debt	425,000	900,000
Dividends paid to common shareholders	(39,736)	(29,194)
Dividends paid to preferred shareholders	(7,678)	(7,678)
Stock options exercised	4,897	1,985
Repurchases of common stock	(162,138)	0
Excess tax benefit from share-based compensation	2,660	201
Restricted stock activity	(4,461)	(468)
Net cash provided by financing activities	947,816	327,571
Decrease in cash and cash equivalents	(156,093)	(83,228)
Cash and cash equivalents at beginning of period	485,489	469,630
Cash and cash equivalents at end of period	329,396	386,402
Supplemental Cash Flow Information
Income tax payments (refunds), net	9,109	4,693
Interest paid	86,451	83,861
Non-cash Investing Activities:
Premises and equipment transferred to other assets held for sale	1,477	16,613
Loans foreclosed and transferred to other real estate	23,862	35,495
Dispositions:
Fair value of non-cash assets sold	0	(100,982)
Fair value of liabilities sold	$ 0	$ (191,553)