Valuation And Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reserves for doubtful accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 4,702	$ 4,576	$ 4,523
Charges to Costs and Expenses	562	390	591
Write-Offs/Cash Payments	(813)	(969)	(1,660)
Foreign Currency Translation	(870)	705	1,122
Balance at End of Year	3,581	4,702	4,576
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	6,212	6,211	4,891
Charges to Costs and Expenses	3,489	402	1,789
Write-Offs/Cash Payments	(226)	0	(679)
Foreign Currency Translation	(21)	(401)	210
Balance at End of Year	$ 9,454	$ 6,212	$ 6,211