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 and leases	$ 115,574	$ 107,355	$ 115,789
Interest on loans held for sale	841	577	534
Interest on deposits with banks	111	77	177
Interest and dividends on investment securities:
Taxable	17,951	22,096	24,624
Exempt from federal income taxes	9,392	9,363	7,222
Interest on federal funds sold	1	2	3
Total interest income	143,870	139,470	148,349
Interest Expense:
Interest on deposits	7,357	11,002	16,934
Interest on retail repurchase agreements and federal funds purchased	204	212	269
Interest on advances from FHLB	14,131	14,397	14,599
Interest on subordinated debt	959	913	940
Total interest expense	22,651	26,524	32,742
Net interest income	121,219	112,946	115,607
Provision for loan and lease losses	3,649	1,428	25,908
Net interest income after provision for loan and lease losses	117,570	111,518	89,699
Non-interest Income:
Investment securities gains	459	292	796
Total other-than-temporary impairment ("OTTI") losses	(109)	(178)	(1,505)
Portion of OTTI losses recognized in other comprehensive income, before taxes	0	18	993
Net OTTI recognized in earnings	(109)	(160)	(512)
Service charges on deposit accounts	8,910	9,527	10,326
Mortgage banking activities	6,032	3,228	3,664
Wealth management income	15,949	15,646	13,725
Insurance agency commissions	4,490	4,650	5,229
Income from bank owned life insurance	2,616	2,636	2,800
Visa check fees	3,887	3,637	3,325
Other income	4,722	4,044	4,429
Total non-interest income	46,956	43,500	43,782
Non-interest Expenses:
Salaries and employee benefits	62,509	59,625	55,470
Occupancy expense of premises	12,010	11,519	11,477
Equipment expenses	4,871	4,705	4,808
Marketing	2,651	2,389	2,359
Outside data services	5,019	4,159	3,992
FDIC insurance	2,573	3,187	4,497
Amortization of intangible assets	1,881	1,845	1,959
Other expenses	18,413	17,642	16,350
Total non-interest expenses	109,927	105,071	100,912
Income before income taxes	54,599	49,947	32,569
Income tax expense	18,045	15,845	9,049
Net income	36,554	34,102	23,520
Preferred stock dividends and discount accretion	0	0	6,149
Net income available to common stockholders	$ 36,554	$ 34,102	$ 17,371
Net Income Per Share Amounts:
Basic net income per share	$ 1.49	$ 1.42	$ 1.05
Basic net income per common share	$ 1.49	$ 1.42	$ 0.78
Diluted net income per share	$ 1.48	$ 1.41	$ 1.05
Diluted net income per common share	$ 1.48	$ 1.41	$ 0.78
Dividends declared per common share	$ 0.48	$ 0.34	$ 0.04