Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts receivable
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 35,087	$ 30,544	$ 27,261
Charged to Expenses	9,192	12,005	9,825
Deductions	(9,907)	(5,353)	(3,670)
Translation Adjustments	(1,239)	(2,109)	(2,872)
Balance at End of Period	33,133	35,087	30,544
Deferred tax valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	26,329	29,561	37,044
Charged to Expenses	2,160	6,283	1,742
Deductions	(9,517)	(8,068)	(6,056)
Translation Adjustments	(65)	(1,447)	(3,169)
Balance at End of Period	$ 18,907	$ 26,329	$ 29,561