Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for doubtful accounts	$ 6,797	$ 18,770
Revenue recognition	60,099	46,953
Net operating loss carryforwards	972	577
Share based compensation	7,544	3,510
Deferred revenue	1,340	879
Other temporary differences	1,147	1,481
Total gross deferred taxes assets	77,899	72,170
Less: valuation allowance	(75,804)	(70,061)
Total deferred taxes assets	2,095	2,109
Deferred tax liabilities:
Fixed assets	1,486	1,789
Total gross deferred taxes liabilities	1,486	1,789
Net deferred taxes assets	$ 609	$ 320