Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income
Loans and leases	$ 238,137	$ 231,453
Investment securities:
U. S. Treasury	739	3,210
Government agency	4,332	5,047
Residential mortgage-backed securities	1,889	2,653
Corporate bonds	1,199	2,176
State, county and municipal	12	13
Other	131	259
Total investment securities interest and dividend income	8,302	13,358
Overnight investments	313	389
Total interest income	246,752	245,200
Interest expense
Deposits	16,472	29,820
Short-term borrowings	1,391	1,697
Long-term obligations	7,937	9,696
Total interest expense	25,800	41,213
Net interest income	220,952	203,987
Provision for loan and lease losses	30,715	44,419
Net interest income after provision for loan and lease losses	190,237	159,568
Noninterest income
Gain on acquisitions	0	63,474
Cardholder and merchant services	22,450	26,780
Service charges on deposit accounts	14,846	15,790
Wealth management services	13,755	13,288
Fees from processing services	8,562	7,246
Securities gains (losses)	(45)	(449)
Other service charges and fees	3,441	5,957
Mortgage income	4,611	2,315
Insurance commissions	2,756	2,534
ATM income	1,455	1,590
Adjustments for FDIC receivable for loss share agreements	(26,796)	(10,379)
Other	1,908	1,434
Total noninterest income	46,943	129,580
Noninterest expense
Salaries and wages	75,684	75,804
Employee benefits	20,249	19,649
Occupancy expense	18,607	18,313
Equipment expense	18,166	17,391
FDIC insurance expense	3,057	8,225
Foreclosure-related expenses	4,621	5,488
Other	42,947	45,158
Total noninterest expense	183,331	190,028
Income before income taxes	53,849	99,120
Income taxes	18,354	37,360
Net income	$ 35,495	$ 61,760
Average shares outstanding (in shares)	10,283,842	10,434,453
Net income per share (in dollars per share)	$ 3.45	$ 5.92