UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2009	$ 175,672	$ 17,890	$ 160,230	$ (2,448)
Balance (in shares) at Dec. 31, 2009		23,681
Comprehensive income:
Net income	18,075	0	18,075	0
Reclassification adjustment for unrealized loss from pension plans included in net income, net of tax	2,596	0	0	2,596
Net unrealized gain from pension plans, net of tax	(148)	0	0	(148)
Total comprehensive income	20,523
Dividends declared ($0.33 per share)	(7,833)	0	(7,833)	0
Dividends reinvested in common stock	520	520	0	0
Dividends reinvested in common stock(in shares)		29
Stock-based compensation	792	792	0	0
Common stock issued through exercise of incentive stock options	561	561	0	0
Common stock issued through exercise of incentive stock options (in shares)		57
Net excess tax benefit from stock options exercised	70	70	0	0
Balance at Dec. 31, 2010	190,305	19,833	170,472	0
Balance (in shares) at Dec. 31, 2010		23,767
Comprehensive income:
Net income	9,021	0	9,021	0
Total comprehensive income	9,021
Stock-based compensation	1,335	1,335	0	0
Common stock issued for share awards	0	0	0	0
Common stock issued for share awards (in shares)		19
Common stock repurchased	(92)	(92)	0	0
Common stock repurchased (in shares)		(5)
Common stock issued	10	10	0	0
Balance at Sep. 30, 2011	$ 200,579	$ 21,086	$ 179,493	$ 0
Balance (in shares) at Sep. 30, 2011		23,781