Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
ASSETS
Cash and due from banks	$ 523,027	$ 571,171	$ 421,836
Interest-bearing deposits in banks	119,543	346,651	487,654
Total cash and cash equivalents	642,570	917,822	909,490
Investment securities:
Held-to-maturity	3,052,118	2,935,688	2,551,860
Available-for-sale	3,478,420	3,273,174	3,299,392
Other investments	148,433	180,803	267,565
Loans held for sale	21,632	11,622	22,855
Loans	14,969,627	14,300,972	14,143,423
Allowance for loan losses	(142,036)	(141,252)	(147,714)
Net loans	14,827,591	14,159,720	13,995,709
Premises and equipment, net	315,770	327,054	316,877
Goodwill	741,740	741,740	741,740
Intangible assets	76,886	82,755	88,419
Covered other real estate	51,072	65,234	67,786
Accrued interest receivable and other assets	1,208,199	1,216,416	1,273,180
Total assets	24,564,431	23,912,028	23,534,873
Deposits:
Noninterest-bearing	5,525,484	5,459,029	5,277,647
Interest-bearing	3,028,479	3,026,735	2,504,368
Savings and money market accounts	8,476,096	8,587,167	8,520,806
Certificates and other time deposits	2,268,337	2,460,670	2,816,901
Total deposits	19,298,396	19,533,601	19,119,722
Federal funds purchased and securities sold under agreements to repurchase	1,218,855	851,535	844,871
Wholesale borrowings	649,021	200,600	201,337
Long-term debt	324,433	324,428	324,422
Accrued taxes, expenses and other liabilities	281,988	298,970	393,612
Total liabilities	21,772,693	21,209,134	20,883,964
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: June 30, 2014 and December 31, 2013 - 170,183,540 shares; June 30, 2013 - 170,179,911 shares	127,937	127,937	127,937
Capital surplus	1,387,253	1,390,643	1,386,063
Accumulated other comprehensive loss	(39,507)	(66,876)	(71,897)
Retained earnings	1,335,371	1,277,975	1,235,530
Treasury stock, at cost: June 30, 2014 - 4,790,517 December 31, 2013 - 5,127,332 shares; June 30, 2013 - 5,134,463 shares	(122,316)	(129,785)	(129,724)
Total shareholders' equity	2,791,738	2,702,894	2,650,909
Total liabilities and shareholders' equity	$ 24,564,431	$ 23,912,028	$ 23,534,873