Basis of Preparation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Accounting Policies [Abstract]
Minimum ownership percentage of investments in affiliates required to be accounted for under the equity method	20.00%
Maximum ownership percentage of investments in affiliates required to be accounted for under the equity method	50.00%
Maximum maturity duration considered to be cash and cash equivalents	3 months
Minimum maturity duration of short-term, highly liquid, variable-rate instruments	3 months
Maximum maturity duration of short-term, highly liquid, variable-rate instruments	6 months
Components of inventory:
Raw materials and supplies	$ 69,833		$ 64,832
Work in process	41,093		36,045
Finished goods	56,929		48,945
Inventories, net	167,855		149,822
Changes in the Company's consolidated warranty reserve:
Beginning balance	13,181	13,372
Warranty expense	989	2,171
Warranty usage	(1,973)	(1,982)
Ending balance	$ 12,197	$ 13,561