Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest Income
Interest and fees on loans	$ 193,193	$ 197,897	$ 192,247
Interest on investment securities:
Taxable	9,890	9,423	11,363
Tax-exempt	5,931	5,860	4,999
Dividends on nonmarketable equity securities	1,041	965	766
Interest on deposits with the Federal Reserve Bank	703	1,097	1,055
Total interest income	210,758	215,242	210,430
Interest Expense
Interest on deposits	21,782	29,293	35,895
Interest on short-term borrowings	426	524	650
Interest on FHLB advances	1,005	1,572	2,765
Total interest expense	23,213	31,389	39,310
Net Interest Income	187,545	183,853	171,120
Provision for loan losses	18,500	26,000	45,600
Net Interest Income after Provision for Loan Losses	169,045	157,853	125,520
Noninterest Income
Service charges and fees on deposit accounts	19,581	18,452	18,562
Wealth management revenue	11,763	11,104	10,106
Other charges and fees for customer services	11,415	10,501	9,599
Mortgage banking revenue	6,597	3,881	3,925
Gain on the sale of merchant card services	1,280	0	0
Other	1,236	462	280
Total Noninterest Income	51,872	44,400	42,472
Operating Expenses
Salaries, wages and employee benefits	84,383	74,493	68,416
Occupancy	12,413	12,974	11,491
Equipment and software	13,112	11,935	13,446
Other	39,201	42,601	43,449
Total Operating Expenses	149,109	142,003	136,802
Income Before Income Taxes	71,808	60,250	31,190
Federal income tax expense	20,800	17,200	8,100
Net Income	$ 51,008	$ 43,050	$ 23,090
Net Income Per Common Share:
Basic (in dollars per share)	$ 1.86	$ 1.57	$ 0.88
Diluted (in dollars per share)	$ 1.85	$ 1.57	$ 0.88
Cash Dividends Declared and Paid Per Common Share	$ 0.82	$ 0.80	$ 0.80