SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts
Movement in valuation and qualifying accounts
Balance at Beginning of Year		$ 4,039	$ 8,059	$ 7,919
Additions Charged to Expenses (Income)		123	(2,203)	6,653
Charge-Offs		(454)	(1,839)	(6,514)
Other	[1]	16	22	1
Balance at End of Year		3,724	4,039	8,059
Valuation allowance for deferred income tax assets
Movement in valuation and qualifying accounts
Balance at Beginning of Year		4,789	6,161	6,317
Additions Charged to Expenses (Income)		0	(2,578)	451
Charge-Offs		0	0	0
Other	[1]	0	1,206	(607)
Balance at End of Year		$ 4,789	$ 4,789	$ 6,161

[1] Primarily the impact of currency changes