Income Taxes - Schedule of Components of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred income tax assets:
Net operating loss carryforwards	$ 95,342	$ 66,340
Stock-based compensation	25,278	24,192
Accrued expenses	3,338	4,016
Research and development tax credits	543	543
Other	371	306
Gross deferred tax assets	124,872	95,397
Valuation allowance	(115,689)	(84,167)	$ (64,449)	$ (47,858)
Net deferred tax assets	9,183	11,230
Deferred tax liabilities:
Property, equipment and software	(5,424)	(6,734)
Intangible assets and goodwill	(6,753)	(6,909)
Gross deferred tax liabilities	(12,177)	(13,643)
Total net deferred tax liabilities	$ (2,994)	$ (2,413)