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
Loans and leases	$ 967,737	$ 914,545	$ 659,537
Investment securities:
U. S. Treasury	8,248	24,569	43,525
Government agency	19,848	12,341	21,908
Residential mortgage-backed securities	9,235	6,544	4,812
Corporate bonds	7,975	8,721	6,283
State, county and municipal	174	75	278
Other	548	227	1,085
Total investment securities interest and dividend income	46,028	52,477	77,891
Overnight investments	1,394	2,346	731
Total interest income	1,015,159	969,368	738,159
Interest expense
Deposits	101,888	149,195	183,759
Short-term borrowings	5,993	5,189	4,882
Long-term obligations	36,311	40,741	39,003
Total interest expense	144,192	195,125	227,644
Net interest income (loss)	870,967	774,243	510,515
Provision for loan and lease losses	232,277	143,519	79,364
Net interest income after provision for loan and lease losses	638,690	630,724	431,151
Noninterest income
Gain on acquisitions	150,417	136,000	104,434
Cardholder and merchant services	110,822	107,575	95,376
Service charges on deposit accounts	63,775	73,762	78,028
Wealth management services	54,974	51,378	46,071
Fees from processing services	30,487	29,097	30,904
Mortgage income	12,214	9,699	10,435
Insurance commissions	9,165	8,650	8,129
ATM income	6,020	6,656	6,856
Other service charges and fees	22,647	20,820	16,411
Securities gains (losses)	(288)	1,952	(511)
Adjustments for FDIC receivable for loss share agreements	(19,305)	(46,806)	2,800
Other	23,438	7,431	4,518
Total noninterest income	464,366	406,214	403,451
Noninterest expense
Salaries and wages	308,088	297,897	264,342
Employee benefits	72,526	64,733	64,390
Occupancy	74,832	72,766	66,266
Equipment	69,951	66,894	60,310
FDIC deposit insurance	16,459	23,167	29,344
Foreclosure-related expenses	46,133	20,439	15,107
Other	204,936	187,480	151,744
Total noninterest expense	792,925	733,376	651,503
Income before income taxes	310,131	303,562	183,099
Income taxes	115,103	110,518	66,768
Net income	$ 195,028	$ 193,044	$ 116,331
PER SHARE INFORMATION
Net income per share (in dollars per share)	$ 18.80	$ 18.50	$ 11.15
Dividends per share (in dollars per share)	$ 1.20	$ 1.20	$ 1.20
Average shares outstanding (in shares)	10,376,445	10,434,453	10,434,453