Other Current Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Other Current Liabilities
Accrued payroll and related benefits	$ 13,569		$ 15,748
Current portion of pension and other postretirement benefit liabilities	1,352		1,389
Accrued warranty expense	1,414	1,408	1,327
Accrued interest	382		1,563
Deferred income	10,016		10,834
Income and other taxes payable	357		202
Liabilities related to assests held for sale	2,245
Other accrued expenses	6,270		9,112
Total	35,605		40,175
Standard product warranty
Warranty period, minimum	1 year
Warranty period, maximum	10 years
Accrued warranty expense activity
Beginning balance	1,327	1,242	1,242
Additions	282	321	1,099
Claims and reversals	(170)	(177)	(1,031)
Foreign currency translation impact	(25)	22	17
Ending balance	$ 1,414	$ 1,408	$ 1,327