Consolidated Statements of Shareholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at Dec. 31, 2009	$ 271,317	$ 234	$ 49,264	$ 225,195	$ 2,353	$ (5,729)
Net income	18,204			18,204
Unrealized appreciation of investment securities, net of tax of $3.4 and $2.4 million for six months ended June 30, 2011 and 2010, respectively	4,375				4,375
Comprehensive income	22,579
Dividends on common stock	(3,115)			(3,115)
Issuance of 11,502 and 41,579 treasury shares upon exercise of options, stock award grants and restricted stock issued, net of forfeitures for six months ended June 30, 2011 and 2010, respectively	444		387			57
Net tax effect from exercise/vesting of stock-based compensation	(50)		(50)
Stock compensation expense	485		485
Balance at Jun. 30, 2010	291,660	234	50,086	240,284	6,728	(5,672)
Balance at Dec. 31, 2010	309,578	234	50,273	258,473	6,251	(5,653)
Net income	17,731			17,731
Unrealized appreciation of investment securities, net of tax of $3.4 and $2.4 million for six months ended June 30, 2011 and 2010, respectively	6,287				6,287
Comprehensive income	24,018
Dividends on common stock	(3,502)			(3,502)
Issuance of 11,502 and 41,579 treasury shares upon exercise of options, stock award grants and restricted stock issued, net of forfeitures for six months ended June 30, 2011 and 2010, respectively	(120)		(136)			16
Net tax effect from exercise/vesting of stock-based compensation	54		54
Stock compensation expense	413		413
Balance at Jun. 30, 2011	$ 330,441	$ 234	$ 50,604	$ 272,702	$ 12,538	$ (5,637)