Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Interest income
Interest on loans	$ 178,309		$ 174,450		$ 177,064
Taxable interest and dividends on securities	16,681		20,326		23,984
Nontaxable interest and dividends on securities	82		331		673
Interest on loans held for sale	988		482		666
Interest on federal funds sold	132		162		337
Total interest and dividend income	196,192		195,751		202,724
Interest expense
Interest on deposits	10,703		13,355		20,254
Interest on borrowings	12,690		15,317		18,509
Total interest expense	23,393		28,672		38,763
Net interest income	172,799		167,079		163,961
Provision for loan losses	18,056		11,482		18,655
Net interest income after provision for loan losses	154,743		155,597		145,306
Noninterest income
Service charges on deposit accounts	15,930		16,628		13,624
Investment management	14,779		13,532		11,723
Interchange and ATM fees	9,783		7,733		5,084
Mortgage banking income	6,500		4,197		5,041
Loan level derivative income	3,457		2,093		1,364
Increase in cash surrender value of life insurance policies	3,114		3,170		3,192
Gains realized on life insurance policies	1,307
Net gain on sales of securities	5		723		458
Gross change on OTTI securities	678		53		497
Less: portion of OTTI losses recognized in OCI	(754)		(296)		(831)
Net impairment losses recognized in earnings on securities	(76)		(243)		(334)
Other noninterest income	7,217		4,867		6,754
Total noninterest income	62,016		52,700		46,906
Noninterest expenses
Salaries and employee benefits	84,014		81,275		76,983
Occupancy and equipment expenses	17,307		16,916		16,011
Merger and acquisition expenses	6,741
Data processing & facilities management	4,644		4,891		5,773
Advertising expense	3,949		3,876		2,171
FDIC assessment	3,232		3,496		5,247
Consulting expense	2,801		2,660		2,523
Telecommunications	2,324		2,092		2,101
Goodwill impairment	2,227	[1]		[1]		[1]
Legal fees	2,223		2,262		3,277
Prepayment fee on borrowings	7		757
Other noninterest expenses	29,990		27,488		25,659
Total noninterest expenses	159,459		145,713		139,745
Income before income taxes	57,300		62,584		52,467
Provision for income taxes	14,673		17,148		12,227
Net income	$ 42,627		$ 45,436		$ 40,240
Basic earnings per share (in dollars per share)	$ 1.96		$ 2.12		$ 1.90
Diluted earnings per share (in dollars per share)	$ 1.95		$ 2.12		$ 1.90
Weighted average common shares (basic) (in shares)	21,782,499		21,422,757		21,178,117
Common share equivalents (in shares)	29,817		28,830		25,798
Weighted average common shares (diluted) (in shares)	21,812,316		21,451,587		21,203,915
Cash dividends declared (in dollars per share)	$ 0.84		$ 0.76		$ 0.72

[1] Amount represents the total amount of goodwill relating to Compass Exchange Advisors, LLC, which was acquired in January 2007.