Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 30,977	$ 34,938	$ 37,636
Other comprehensive income/(loss), before tax:
Foreign currency translation adjustments	11,865	(13,070)	(10,208)
Pension settlement	118,350	327	(1,048)
Pension and postretirement plan remeasurement	(48,233)	(28,375)	(19,645)
Amortization of pension liability adjustments:
Transition obligation	79	83	94
Prior service cost/(credit)	(3,631)	(3,629)	(3,650)
Net actuarial loss	7,438	8,694	7,661
Derivative valuation adjustment	(467)	(3,799)	(452)
Income taxes related to items of other comprehensive (loss)/income:
Pension settlement	(39,146)	(72)	160
Pension and postretirement plan remeasurement	14,711	6,382	3,002
Amortization of pension liability adjustment	(1,360)	(1,159)	(626)
Derivative valuation adjustment	182	1,481	176
Other comprehensive income/(loss), after tax	59,788	(33,137)	(24,536)
Comprehensive income	$ 90,765	$ 1,801	$ 13,100