Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance - Beginning of the year	$ 5,242	$ 3,881	$ 4,539
Provisions	7,327	5,488	5,547
Utilizations	(7,392)	(4,264)	(6,063)
Currency translation adjustment	(38)	137	(142)
Balance - End of the year	5,139	5,242	3,881
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance - Beginning of the year	15,021	12,546	14,404
Provisions	874	2,506	2,917
Utilizations	(1,230)	(31)	4,775
Balance - End of the year	$ 14,665	$ 15,021	$ 12,546