Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Federal tax	$ 21,907	$ 8,762	$ 14,214
State income taxes, net of federal tax provision	(15)	(65)	(152)
Foreign income taxed at lower tax rates	(23,515)	(6,955)	(10,126)
U.S. tax impact of foreign operations	6,726	324	2,046
Foreign withholding taxes	4,343	4,834	2,268
Research and development	(2,643)	(2,241)	(2,068)
Liability for unrecognized tax benefits	2,672	1,815	88
Valuation allowance	2,077	(2,600)	3,580
Provision-to-return adjustments	131	(61)	994
Employee stock-based compensation	1,537
U.S. Tax Cuts and Jobs Act	45,908
Other	3,197	2,745	3,238
Total income tax provision	$ 62,325	$ 6,558	$ 14,082
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income tax rate, Federal tax	35.00%	35.00%	35.00%
Income tax rate, State income taxes, net of federal tax provision		(0.30%)	(0.40%)
Income tax rate, Foreign income taxed at lower tax rates	(37.60%)	(27.80%)	(24.90%)
Income tax rate, U.S. tax impact of foreign operations	10.70%	1.30%	5.00%
Income tax rate, Foreign withholding taxes	6.90%	19.30%	5.60%
Income tax rate, Research and development	(4.20%)	(9.00%)	(5.10%)
Income tax rate, Liability for unrecognized tax benefits	4.30%	7.30%	0.20%
Income tax rate, Valuation allowance	3.30%	(10.40%)	8.80%
Income tax rate, Provision-to-return adjustment	0.20%	(0.20%)	2.40%
Income tax rate, Employee stock-based compensation	2.50%
Income tax rate, U.S. Tax Cuts and Jobs Act	73.40%
Income tax rate, Other	5.10%	11.00%	8.10%
Income tax rate, Total	99.60%	26.20%	34.70%