CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data	Total	Common stock [Member]	Additional paid-in capital [Member]	Accumulated other comprehensive income (loss) Pensions [Member]	Accumulated Other Comprehensive Income (Loss) [Member] OPEB [Member]	Retained earnings [Member]	Treasury stock [Member]
Balance at Dec. 31, 2009	$ 159,761	$ 125	$ 100,111	$ (158,401)	$ 25,871	$ 192,851	$ (796)
Balance, Shares at Dec. 31, 2009		12,102,000
Net income	12,014					12,014
Other comprehensive income (loss), net	35,223			41,656	(6,433)
Balance at Dec. 31, 2010	206,998	125	100,111	(116,745)	19,438	204,865	(796)
Balance, Shares at Dec. 31, 2010		12,102,000
Net income	30,211					30,211
Retirement of treasury stock	(456)	(4)	(1,248)				796
Other comprehensive income (loss), net	(84,786)			(75,807)	(8,979)
Other, net	161		161
Balance at Dec. 31, 2011	152,128	121	99,024	(192,552)	10,459	235,076
Balance, Shares at Dec. 31, 2011	12,101,932	12,102,000
Net income	20,224					20,224
Other comprehensive income (loss), net	5,051			12,821	(7,770)
Balance at Dec. 31, 2012	$ 177,403	$ 121	$ 99,024	$ (179,731)	$ 2,689	$ 255,300
Balance, Shares at Dec. 31, 2012	12,101,932	12,102,000