Consolidated Statement of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)
Balance at Dec. 31, 2012	$ 205,075	$ 7,273	$ 17,731	$ 174,650	$ 5,421
Balance (in shares) at Dec. 31, 2012		13,915
Increase (Decrease) in Stockholders' Equity
Net income	20,857			20,857
Other comprehensive loss, net of tax	(5,520)				(5,520)
Stock compensation expense	1,473		1,473
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards	1,969	309	1,784	(124)
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards (in shares)		93
Stock issued for non-vested restricted stock		184	1,083	(1,267)
Stock issued for non-vested restricted stock (in shares)		55
Stock issued for acquisition	12,198	1,769	10,429
Stock issued for acquisition (in shares)		531
Cash dividends, $0.60 per share	(8,602)			(8,602)
Shares repurchased or cancelled	(915)	(137)	(882)	104
Shares repurchased or cancelled (in shares)		(40)
Balance at Sep. 30, 2013	$ 226,535	$ 9,398	$ 31,618	$ 185,618	$ (99)
Balance (in shares) at Sep. 30, 2013		14,554