UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2010	$ 19,833	$ 170,472	$ 190,305
Balance (in shares) at Dec. 31, 2010	23,767
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	12,993	12,993
Dividends declared	0	(7,849)	(7,849)
Dividends reinvested in common stock	529	0	529
Dividends reinvested in common stock (in shares)	51
Stock based compensation	1,718	0	1,718
Common stock issued through exercise of incentive stock options	37	0	37
Common stock issued through exercise of incentive stock options (in shares)	5
Common stock issued for share awards	0	0	0
Common stock issued for share awards (in shares)	19
Common stock issued	13	0	13
Common stock issued (in shares)	1
Common stock repurchased	(92)	0	(92)
Common stock repurchased (in shares)	(5)
Net excess tax benefit from stock options exercised and stock awards	5	0	5
Balance at Dec. 31, 2011	22,043	175,616	197,659
Balance (in shares) at Dec. 31, 2011	23,838
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	0	4,466	4,466
Stock based compensation	403	0	403
Common stock issued for share awards	0	0	0
Common stock issued for share awards (in shares)	16
Common stock issued	2	0	2
Common stock issued (in shares)	0
Common stock repurchased	(47)	0	(47)
Common stock repurchased (in shares)	(5)
Net excess tax benefit from stock options exercised and stock awards	(35)	0	(35)
Balance at Mar. 31, 2012	$ 22,366	$ 180,082	$ 202,448
Balance (in shares) at Mar. 31, 2012	23,849