Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest, fee, and dividend income
Interest and fees on loans and leases	$ 204,370	$ 213,429	$ 220,324
Securities available for sale	31,083	36,167	45,972
Securities held to maturity	2,886	3,968	4,894
Other	1,658	2,174	2,203
Total interest, fee, and dividend income	239,997	255,738	273,393
Interest expense
Deposits	23,020	30,354	48,496
Short-term borrowings	205	402	552
Long-term debt	14,404	18,314	23,629
Trust preferred debentures	2,092	4,140	4,247
Total interest expense	39,721	53,210	76,924
Net interest income	200,276	202,528	196,469
Provision for loan and lease losses	20,737	29,809	33,392
Net interest income after provision for loan and lease losses	179,539	172,719	163,077
Noninterest income
Service charges on deposit accounts	21,464	24,041	27,165
Insurance and other financial services revenue	20,843	18,867	17,725
Trust	8,864	7,722	6,719
Net securities gains	150	3,274	144
Bank owned life insurance income	3,085	3,316	3,135
ATM and debit card fees	11,642	10,035	9,339
Retirement plan administration fees	8,918	10,356	9,086
Other	5,345	6,277	6,818
Total noninterest income	80,311	83,888	80,131
Noninterest expense
Salaries and employee benefits	99,212	93,718	85,565
Occupancy	16,363	15,350	14,864
Equipment	8,864	8,317	8,139
Data processing and communications	12,271	12,347	13,238
Professional fees and outside services	8,921	9,032	10,508
Office supplies and postage	6,073	6,102	5,857
Amortization of intangible assets	3,046	3,072	3,246
Loan collection and other real estate owned	2,631	3,036	2,766
Advertising	3,460	3,487	3,455
FDIC expenses	4,267	6,081	8,408
Prepayment penalty on long-term debt	0	4,526	810
Other	15,568	13,223	13,710
Total noninterest expense	180,676	178,291	170,566
Income before income tax expense	79,174	78,316	72,642
Income tax expense	21,273	20,912	20,631
Net income	$ 57,901	$ 57,404	$ 52,011
Basic (in dollars per share)	$ 1.72	$ 1.67	$ 1.54
Diluted (in dollars per share)	$ 1.71	$ 1.66	$ 1.53