Income Taxes - Reconciliation of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Benefit from for income taxes at U.S. Federal statutory rate	$ (3,559)	$ (29,648)	$ (28,150)
Differential in rates on foreign earnings	4,299	15,920	11,741
Non-deductible amortization expense	0	0	617
Tax Reform Tax rate reduction	0	14,527
Change in valuation allowance	1,449	(2,834)	4,465
Change in liabilities for uncertain tax positions	(250)	(2,009)	(960)
Non-deductible stock-based compensation	1,363	1,934	1,480
Permanent Differences	1,096	380	441
Adjustments related to tax positions taken during prior years	184	(473)	(163)
Adjustments made under intercompany transactions	0	0	1,779
Tax Refund	(305)	(834)
Other	(190)	1,285	634
Total provision for (benefit from) income taxes	$ 4,087	$ (1,752)	$ (8,116)