Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Allowance for doubtful accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 27,678	$ 33,181	$ 33,133
Charged to Expenses	9,868	11,914	8,022
Deductions	(8,687)	(8,690)	(8,751)
Translation Adjustments	(103)	772	777
Balance at End of Period	28,756	27,678	33,181
Liability recognized in accordance with ASC 606	(28,756)	(27,678)	(33,181)	$ (23,682)
Allowance for doubtful accounts receivable | Accounting Standards Update 2014-09
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Liability recognized in accordance with ASC 606				$ 9,500
Deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	23,072	20,178	18,907
Charged to Expenses	719	5,683	1,411
Deductions	(2,154)	(2,599)	(1,275)
Translation Adjustments	(19)	(190)	1,135
Balance at End of Period	21,618	23,072	20,178
Liability recognized in accordance with ASC 606	$ (21,618)	$ (23,072)	$ (20,178)