Summary of Significant Accounting Policies (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Warranty activity
Warranty reserves, beginning of the year	$ 5,956	$ 6,281	$ 7,844
Accruals for warranties issued during the year	4,596	5,528	6,439
Reductions related to pre-existing warranties	(3,730)	(3,792)	(5,611)
Standard Product Warranty Accrual, Additions from Business Acquisition	249	0	0
Warranties paid	(1,293)	(2,078)	(2,372)
Other (principally foreign currency translation)	(67)	17	(19)
Warranty reserves, beginning of the year	5,711	5,956	6,281
Self-insurance
Loss Contingencies [Line Items]
Insurance expense from continuing operations	14,300	16,400	15,000
Decrease in pre-tax insurance expense due to retrospective insurance reserve adjustments from continuing operations	2,700	2,600	$ 5,400
Liabilities for asserted and unasserted claims	60,300	33,600
Liabilities covered by insurance carriers	$ 34,200	$ 4,100