Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Warranty activity
Warranty reserves, beginning of the year	$ 5,037,000	$ 4,078,000	$ 2,863,000
Accruals for warranties issued during the year	4,003,000	4,399,000	4,623,000
Reductions related to pre-existing warranties	(1,769,000)	(1,447,000)	(1,388,000)
Warranties paid	(1,677,000)	(2,054,000)	(2,059,000)
Other (principally foreign currency translation)	2,000	61,000	39,000
Warranty reserves, end of the year	5,596,000	5,037,000	4,078,000
Financial instruments and hedging
Maximum typical term of foreign currency forward exchange contracts (in days)	90 days
Self insurance
Accrued Insurance and Loss Reserves
Insurance expense from continuing operations	37,000,000	38,500,000	38,700,000
Decrease in pre-tax insurance expense due to retrospective insurance reserve adjustments from continuing operations	2,700,000	2,500,000	3,700,000
Liabilities for asserted and unasserted claims	85,900,000	88,000,000
Liabilities covered by insurance carriers	$ 2,600,000	$ 4,300,000
Maximum settlement period of current insurance liability (in years)	1