Consolidated Statements of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2010	$ 196,777	$ 10,305	$ 121,074	$ 124,872	$ (59,474)
Stock-based compensation	1,636		1,636
Comprehensive income:
Net income	21,309			21,309
Other comprehensive income (loss)	(19,816)				(19,816)
Comprehensive income	1,493
Issuance of common stock including excess tax benefits of $47, $16 and $5 for 2011, 2012 and 2013	399	21	378
Cash dividends ($0.72 per share)	(7,433)			(7,433)
Ending Balance at Dec. 31, 2011	192,872	10,326	123,088	138,748	(79,290)
Stock-based compensation	1,058		1,058
Comprehensive income:
Net income	8,355			8,355
Other comprehensive income (loss)	(3,085)				(3,085)
Comprehensive income	5,270
Issuance of common stock including excess tax benefits of $47, $16 and $5 for 2011, 2012 and 2013	338	20	318
Cash dividends ($0.72 per share)	(7,445)			(7,445)
Ending Balance at Dec. 31, 2012	192,093	10,346	124,464	139,658	(82,375)
Stock-based compensation	996		996
Comprehensive income:
Net income	12,437			12,437
Other comprehensive income (loss)	36,510				36,510
Comprehensive income	48,947
Issuance of common stock including excess tax benefits of $47, $16 and $5 for 2011, 2012 and 2013	419	27	392
Cash dividends ($0.72 per share)	(7,460)			(7,460)
Ending Balance at Dec. 31, 2013	$ 234,995	$ 10,373	$ 125,852	$ 144,635	$ (45,865)