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 and sales returns and allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 8,882	$ 6,319	$ 5,572
Charged to Costs and Expenses	557	4,920	2,009
Other	(4,649)	1,518	0
Deductions	(1,071)	(3,875)	(1,262)
Balance at End of Period	3,719	8,882	6,319
Deferred tax assets valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	7,961	3,604	4,887
Charged to Costs and Expenses	(894)	740	(1,228)
Other	0	3,617	0
Deductions	(94)	0	(55)
Balance at End of Period	$ 6,973	$ 7,961	$ 3,604