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 income:
Interest and fees on loans, including loans held for sale	$ 144,635	$ 142,109	$ 139,736
Interest and dividends on securities
Taxable	10,133	8,934	9,569
Tax exempt	1,712	1,601	1,845
Interest and dividends on Federal Reserve Bank and Federal Home Loan Bank stock	1,374	1,351	1,402
Other, including interest on federal funds sold	606	516	498
Total interest income	158,460	154,511	153,050
Interest expense:
Interest on deposits	21,282	29,152	39,793
Interest on repurchase agreements and other short-term borrowings	1,625	2,027	2,457
Interest on advances from Federal Home Loan Bank	99	79	1,291
Interest on long-term debt	3,999	3,999	3,999
Total interest expense	27,005	35,257	47,540
Net interest income	131,455	119,254	105,510
Provision for loan losses	13,262	16,484	17,468
Net interest income after provision for loan losses	118,193	102,770	88,042
Noninterest income:
Service charges on deposit accounts	25,576	23,255	21,970
Gains on sales of loans, net	1,749	1,642	4,324
Trust income	6,354	5,846	5,047
Loan related fees	2,372	3,247	3,817
Bank owned life insurance	1,721	1,676	1,241
Securities gains and losses	218	0	654
Other noninterest income	5,842	5,260	4,367
Total noninterest income	43,832	40,926	41,420
Noninterest expense:
Officer salaries and employee benefits	8,379	8,244	8,169
Other salaries and employee benefits	40,416	39,020	35,392
Occupancy, net	7,929	7,058	6,836
Equipment	3,750	3,865	4,679
Data processing	6,495	6,889	6,064
Bank franchise tax	4,290	4,065	3,684
Legal fees	2,644	2,727	2,395
Professional fees	1,256	1,199	1,350
FDIC insurance	3,192	4,410	5,795
Other real estate owned provision and expense	8,604	2,626	3,281
Other noninterest expense	19,432	15,947	16,156
Total noninterest expense	106,387	96,050	93,801
Income before income taxes	55,638	47,646	35,661
Income taxes	16,811	14,612	10,602
Net income	$ 38,827	$ 33,034	$ 25,059
Basic earnings per share (in dollars per share)	$ 2.54	$ 2.17	$ 1.66
Diluted earnings per share (in dollars per share)	$ 2.53	$ 2.16	$ 1.65