Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Noncurrent deferred tax assets:
Allowance for doubtful accounts	$ 119	$ 402
Accrued expenses and other current liabilities	330	684
Stock-based compensation	10,877	16,194
Prepaid rent	1,326	1,448
Deferred revenue	433	899
Noncurrent liabilities	94	337
Net operating loss and credit carryforwards	38,705	46,030
Gross noncurrent deferred tax assets	51,884	65,994
Less: valuation allowance	(10,190)	(13,705)
Deferred tax assets	41,694	52,289
Deferred tax liabilities:
Intangible assets	69,943	91,447
Property and equipment	5,465	7,825
Software development costs	3,251	3,924
Deferred tax liabilities	78,659	103,196
Net deferred tax liabilities	$ 36,965	$ 50,907