Summary of Significant Accounting Policies (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Warranty activity
Warranty reserves, beginning of the year	$ 5,596,000	$ 5,037,000	$ 4,078,000
Accruals for warranties issued during the year	7,935,000	4,003,000	4,399,000
Reductions related to pre-existing warranties	(2,401,000)	(1,769,000)	(1,447,000)
Warranties paid	(1,958,000)	(1,677,000)	(2,054,000)
Other (principally foreign currency translation)	(80,000)	2,000	61,000
Warranty reserves, beginning of the year	9,092,000	5,596,000	5,037,000
Self-insurance
Loss Contingencies [Line Items]
Insurance expense from continuing operations	33,800,000	37,000,000	38,500,000
Decrease in pre-tax insurance expense due to retrospective insurance reserve adjustments from continuing operations	4,300,000	2,700,000	2,500,000
Liabilities for asserted and unasserted claims	82,700,000	85,900,000
Liabilities covered by insurance carriers	$ 3,600,000	$ 2,600,000