Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Interest income
Interest on loans	$ 46,978	$ 43,077
Taxable interest and dividends on securities	3,529	4,527
Nontaxable interest and dividends on securities	11	29
Interest on loans held for sale	268	130
Interest on federal funds sold	34	33
Total interest and dividend income	50,820	47,796
Interest expense
Interest on deposits	2,665	2,739
Interest on borrowings	3,293	3,204
Total interest expense	5,958	5,943
Net interest income	44,862	41,853
Provision for loan losses	1,300	1,600
Net interest income after provision for loan losses	43,562	40,253
Noninterest income
Deposit account fees	4,217	3,889
Interchange and ATM fees	2,328	2,368
Investment management	3,884	3,563
Mortgage banking income	2,281	1,330
Increase in cash surrender value of life insurance policies	746	713
Loan level derivative income	532	328
Other noninterest income	1,736	1,718
Total noninterest income	15,724	13,909
Noninterest expenses
Salaries and employee benefits	22,715	21,436
Occupancy and equipment expenses	5,249	4,300
Advertising expense	1,172	738
Data processing & facilities management	1,184	1,175
FDIC assessment	821	749
Consulting expense	710	626
Merger and acquisition expenses	1,345
Legal fees	503	647
Telecommunications	655	618
Other noninterest expenses	7,215	6,034
Total noninterest expenses	42,920	37,358
Income before income taxes	16,366	16,804
Provision for income taxes	4,114	4,621
Net income	$ 12,252	$ 12,183
Basic earnings per share (in dollars per share)	$ 0.54	$ 0.57
Diluted earnings per share (in dollars per share)	$ 0.54	$ 0.56
Weighted average common shares (basic) (in shares)	22,823,753	21,561,006
Common shares equivalents (in shares)	46,040	24,481
Weighted average common shares (diluted) (in shares)	22,869,793	21,585,487
Cash dividends declared per common share (in dollars per share)	$ 0.22	$ 0.21