Income Taxes - Current and Deferred (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal											$ (423)	$ (9,918)	$ 5,731
State											1,072	(624)	(1,645)
Foreign											11,490	8,975	12,647
Total											12,139	(1,567)	16,733
Deferred:
Federal											25,797	(12,687)	13,665
State											7,694	(2,217)	2,570
Foreign											335	(851)	(3,312)
Total											33,826	(15,755)	12,923
Total, income tax expense (benefit)	$ 6,500	$ 2,000	$ 45,012	$ 444	$ (1,491)	$ (7,862)	$ (3,887)	$ (4,441)	$ (1,132)		45,965	(17,322)	29,656
Components of (Loss) income before income taxes
U.S.											(56,465)	(81,579)	51,797
Foreign											62,990	38,339	69,429
Income (loss) before income tax expense (benefit)		(418)	(1,955)	5,087	$ 3,811	(2,146)	$ (27,798)	$ (9,658)	$ (3,638)		6,525	(43,240)	$ 121,226
Deferred tax assets:
Compensation and benefits		5,912				9,715					5,912	9,715
Net operating loss and capital loss carryover		18,974				19,755					18,974	19,755
Share-based compensation		5,092				6,824					5,092	6,824
Research and development credits		7,438				7,550					7,438	7,550
Foreign tax credits		11,117				12,660					11,117	12,660
Tax benefits on uncertain tax positions		831				1,351					831	1,351
Goodwill and definite-lived intangibles		6,363				8,015					6,363	8,015
Depreciation		3,527				1,167					3,527	1,167
Capitalized software		383									383
Rent		3,013				3,695					3,013	3,695
Other		700				1,564					700	1,564
Total deferred tax assets		63,350				72,296					63,350	72,296
Less: valuation allowance		(58,448)				(20,979)					(58,448)	(20,979)
Total deferred tax assets, net of valuation allowance		4,902				51,317					4,902	51,317
Deferred tax liabilities:
Capitalized software						(12,174)						(12,174)
Indefinite-lived intangibles		(1,695)									(1,695)
Other		(55)				(455)					(55)	(455)
Total deferred tax liabilities		(1,750)				(12,629)					(1,750)	(12,629)
Net deferred tax assets		$ 3,152		42,300		38,688					$ 3,152	$ 38,688
Increase (decrease) in valuation allowance			$ 48,100
Corporate income tax rate as a percentage		35.00%									35.00%	35.00%	35.00%
Valuation allowance		$ 58,448				$ 20,979					$ 58,448	$ 20,979
Expire in 2024
Deferred tax assets:
Foreign tax credits		11,100									11,100
Expire In 2032
Deferred tax assets:
Research and development credits		7,400									7,400
U.S.
Deferred tax assets:
Less: valuation allowance		(37,700)		(42,300)							(37,700)
Deferred tax liabilities:
Increase (decrease) in valuation allowance		900
Valuation allowance		$ 37,700		$ 42,300							$ 37,700
Forecast
Deferred tax liabilities:
Corporate income tax rate as a percentage										21.00%