Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
ASSETS
Cash and due from banks	$ 429,699	$ 571,171	$ 505,228
Interest-bearing deposits in banks	55,629	346,651	742,039
Total cash and cash equivalents	485,328	917,822	1,247,267
Investment securities:
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	3,002,262	2,935,688	2,749,934
Available-for-sale	3,462,990	3,273,174	3,256,259
Other investments	148,421	180,803	270,369
Loans Held-for-sale, Fair Value Disclosure	19,512	11,622	17,813
Loans	15,242,026	14,300,972	14,260,836
Allowance for loan losses	(140,077)	(141,252)	(143,835)
Net loans	15,101,949	14,159,720	14,117,001
Premises and equipment, net	318,690	327,054	324,337
Goodwill	741,740	741,740	741,740
Intangible assets, net	73,953	82,755	85,447
Covered other real estate	51,434	65,234	70,791
Accrued interest receivable and other assets	1,201,928	1,216,416	1,256,772
Total assets	24,608,207	23,912,028	24,137,730
Deposits:
Noninterest-bearing	5,535,886	5,459,029	5,461,674
Interest-bearing	3,043,952	3,026,735	2,815,681
Savings and money market accounts	8,396,064	8,587,167	8,575,292
Certificates and other time deposits	2,391,009	2,460,670	2,636,886
Total deposits	19,366,911	19,533,601	19,489,533
Federal funds purchased and securities sold under agreements to repurchase	1,273,290	851,535	1,049,801
Wholesale borrowings	608,463	200,600	200,858
Long-term debt	249,933	324,428	324,425
Accrued taxes, expenses and other liabilities	289,179	298,970	418,468
Total liabilities	21,787,776	21,209,134	21,483,085
Shareholders' equity:
Preferred Stock, Value, Issued	100,000	100,000	100,000
Common Stock warrant	3,000	3,000	3,000
Common Stock, without par value; authorized 300,000,000 shares; issued: September 30, 2014 and December 31, 2013 - 170,183,540 shares; September 30, 2013 - 170,179,305 shares	127,937	127,937	127,937
Capital surplus	1,390,207	1,390,643	1,388,638
Accumulated other comprehensive loss	(49,583)	(66,876)	(83,613)
Retained earnings	1,371,453	1,277,975	1,248,554
Treasury stock, at cost: September 30, 2014 - 4,799,239; December 31, 2013 - 5,127,332 shares; September 30, 2013 - 5,134,681 shares	(122,583)	(129,785)	(129,871)
Total shareholders' equity	2,820,431	2,702,894	2,654,645
Total liabilities and shareholders' equity	$ 24,608,207	$ 23,912,028	$ 24,137,730