Consolidated Statements Of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest Income
Interest and fees on loans	$ 547,365	$ 543,009	$ 561,252
Interest and dividends on investment securities:
Taxable	108,129	115,593	131,792
Tax-exempt	11,273	10,366	9,682
Dividends	6,655	7,428	8,513
Interest on federal funds sold and other short-term investments	402	416	945
Total interest income	673,824	676,812	712,184
Interest Expense
Savings, NOW and money market	19,876	19,126	24,894
Time	48,291	55,798	93,403
Interest on short-term borrowings	1,154	1,345	4,026
Interest on long-term borrowings and junior subordinated debentures	129,692	137,791	140,547
Total interest expense	199,013	214,060	262,870
Net Interest Income	474,811	462,752	449,314
Provision for credit losses	53,335	49,456	47,992
Net Interest Income After Provision for Credit Losses	421,476	413,296	401,322
Non-Interest Income
Trust and investment services	7,523	7,665	6,906
Insurance commissions	15,627	11,334	10,224
Service charges on deposit accounts	22,610	25,691	26,778
Gains on securities transactions, net	32,068	11,598	8,005
Other-than-temporary impairment losses on securities	(42,775)	(1,393)	(6,339)
Portion recognized in other comprehensive (loss) income (before taxes)	22,807	(3,249)	(13)
Net impairment losses on securities recognized in earnings	(19,968)	(4,642)	(6,352)
Trading gains (losses), net	2,271	(6,897)	(10,434)
Fees from loan servicing	4,337	4,919	4,839
Gains on sales of loans, net	10,699	12,591	8,937
Gains on sales of assets, net	426	619	605
Bank owned life insurance	7,380	6,166	5,700
Change in FDIC loss-share receivable	13,403	6,268
Other	15,921	16,015	17,043
Total non-interest income	112,297	91,327	72,251
Non-Interest Expense
Salary and employee benefits expense	176,307	176,106	163,746
Net occupancy and equipment expense	64,364	61,765	58,974
FDIC insurance assessment	12,759	13,719	20,128
Amortization of other intangible assets	9,315	7,721	6,887
Professional and legal fees	15,312	10,137	7,907
Advertising	8,373	4,052	3,372
Other	50,158	44,182	45,014
Total non-interest expense	336,588	317,682	306,028
Income Before Income Taxes	197,185	186,941	167,545
Income tax expense	63,532	55,771	51,484
Net Income	133,653	131,170	116,061
Dividends on preferred stock and accretion			19,524
Net Income Available to Common Stockholders	$ 133,653	$ 131,170	$ 96,537
Earnings Per Common Share:
Basic	$ 0.79	$ 0.78	$ 0.61
Diluted	$ 0.79	$ 0.78	$ 0.61
Cash Dividends Declared Per Common Share	$ 0.69	$ 0.69	$ 0.69
Weighted Average Number of Common Shares Outstanding:
Basic	169,928,460	169,112,901	159,259,476
Diluted	169,929,590	169,121,584	159,260,229