Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
ASSETS
Cash and due from banks	$ 183,430	$ 244,223	$ 188,789
Interest-bearing deposits in banks	163,673	13,791	301,196
Total cash and cash equivalents	347,103	258,014	489,985
Investment securities
Held-to-maturity	665,589	622,121	100,840
Available-for-sale	3,243,835	2,920,971	3,491,647
Other investments	140,984	140,717	140,713
Loans held for sale	14,459	23,683	42,447
Noncovered loans:
Commercial loans	5,888,337	5,866,489	5,220,051
Mortgage loans	451,522	445,211	428,950
Installment loans	1,322,795	1,328,258	1,259,930
Home equity loans	812,458	806,078	739,548
Credit card loans	140,721	146,387	140,618
Loans and Leases Receivable, Gross, Consumer, Lease Financing	164,137	139,236	74,112
Total noncovered loans	8,779,970	8,731,659	7,863,209
Allowance for noncovered loan losses	(98,843)	(98,942)	(103,849)
Net non-covered loans	8,681,127	8,632,717	7,759,360
Covered loans (includes loss share receivable of $95.6 million, $113.7 million and $171.1 million at March 31, 2013, December 31, 2012 and March 31, 2012, respectively)	896,832	1,019,125	1,378,150
Covered Certain Loans Acquired in Transfer not Accounted for as Debt Securities Allowance for Loan Losses	(47,945)	(43,255)	(41,070)
Covered Loans and Leases Receivable Gross Carrying Amount	848,887	975,870	1,337,080
Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered	9,530,014	9,608,587	9,096,440
Premises and equipment, net	177,137	181,149	188,347
Goodwill	460,044	460,044	460,044
Intangible assets	6,055	6,373	7,756
Covered other real estate (includes loss share receivable of $.04 million, $.05 million, and $0.7 million at March 31, 2013, December 31, 2012 and March 31, 2012, respectively)	70,267	59,855	56,411
Accrued interest receivable and other assets	616,997	631,498	596,188
Total assets	15,272,484	14,913,012	14,670,818
Deposits:
Demand-non-interest bearing	3,360,841	3,338,371	3,136,595
Demand-interest bearing	1,371,359	1,287,674	1,119,102
Savings and money market accounts	5,890,369	5,758,123	5,742,547
Certificates and other time deposits	1,303,198	1,375,257	1,649,921
Total deposits	11,925,767	11,759,425	11,648,165
Federal funds purchased and securities sold under agreements to repurchase	826,855	1,104,525	928,760
Wholesale borrowings	136,003	136,883	176,611
Long-term Debt	249,921	0	0
Accrued taxes, expenses and other liabilities	379,088	266,977	333,177
Total liabilities	13,517,634	13,267,810	13,086,713
Shareholders' equity:
Preferred stock, without par value		0	0
Common stock, without par value; authorized 300,000,000 shares; issued: March 31, 2013, December 31, 2012 and March 31, 2012 - 115,121,731 shares	127,937	127,937	127,937
Capital surplus	472,975	475,979	484,491
Accumulated other comprehensive loss	(24,119)	(16,205)	(22,172)
Retained earnings	1,214,889	1,195,850	1,144,210
Treasury stock, at cost: March 31, 2013 - 5,375,905 shares; December 31, 2012 - 5,472,915 shares; March 31, 2012 - 5,935,169 shares	(136,832)	(138,359)	(150,361)
Total shareholders' equity	1,754,850	1,645,202	1,584,105
Total liabilities and shareholders' equity	15,272,484	14,913,012	14,670,818
Preferred stock, without par value: authorized and unissued 7,000,000 shares
Shareholders' equity:
Preferred stock, without par value	0	0	0
Preferred stock, Series A, without par value: designated 800,000 shares; none outstanding
Shareholders' equity:
Preferred stock, without par value	0	0	0
Convertible preferred stock, Series B, without par value: designated 220,000 shares; none outstanding
Shareholders' equity:
Preferred stock, without par value	0	0	0
5.875% Non-Cumulative Perpetual Preferred stock, Series A, without par value: authorized 115,000 shares; 100,000 issued
Shareholders' equity:
Preferred stock, without par value	$ 100,000