Basis of Preparation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 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%		20.00%
Maximum ownership percentage of investments in affiliates required to be accounted for under the equity method	50.00%		50.00%
Maximum maturity duration considered to be cash and cash equivalents	3 months		3 months
Minimum maturity duration of short-term, highly liquid, variable-rate instruments	3 months		3 months
Maximum maturity duration of short-term, highly liquid, variable-rate instruments	6 months		6 months
Components of inventory:
Raw materials and supplies	$ 75,033		$ 75,033		$ 64,832
Work in process	44,108		44,108		36,045
Finished goods	55,923		55,923		48,945
Inventories, net	175,064		175,064		149,822
Changes in the Company's consolidated warranty reserve:
Beginning balance	12,197	13,561	13,181	13,372
Warranty expense	2,613	1,429	3,602	3,602
Warranty usage	(3,562)	(2,141)	(5,535)	(4,125)
Ending balance	$ 11,248	$ 12,849	$ 11,248	$ 12,849