Summary of Significant Accounting Policies (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Warranty activity
Warranty reserves, beginning of the year	$ 5,920	$ 5,243	$ 5,486
Accruals for warranties issued during the year	5,335	4,744	3,837
Reductions related to pre-existing warranties	(2,418)	(2,748)	(3,320)
Standard Product Warranty Accrual, Additions from Business Acquisition	0	0	249
Warranties paid	(2,356)	(1,259)	(942)
Other (principally foreign currency translation)	131	(60)	(67)
Warranty reserves, beginning of the year	6,612	5,920	5,243
Self-insurance
Loss Contingencies [Line Items]
Insurance expense from continuing operations	23,400	15,400	13,500
Decrease in pre-tax insurance expense due to retrospective insurance reserve adjustments from continuing operations	2,100	1,500	$ 2,000
Liabilities for asserted and unasserted claims	28,300	28,700
Liabilities covered by insurance carriers	$ 5,200	$ 3,700