Accrued Product Warrenties Accrued Product Warrenties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Movement in Standard Product Warranty Accrual [Roll Forward]
Accrued product warranties, beginning of period	$ 16,046	$ 18,686
Amounts paid for warranty services	(2,167)	(2,988)
Warranty provisions for products sold	1,835	2,708
Currency translation adjustments and other	280	554
Accrued product warranties, end of period	15,994	18,960
Current accrued product warranties, end of period	13,592	15,888	13,370
Long-term accrued product warranties, end of period	$ 2,402	$ 3,072