Income Taxes - Schedule of Net Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Deferred rent	$ 278	$ 133
AMT credit	11	9
Accrued expenses	2,057	1,474
Deferred revenue	549	292
Net operating loss carryforward	34,662	14,957
Other assets	2,343	1,643
Property and equipment	123
Intangible assets	836
Valuation allowance	(25,079)	(10,911)
Total net deferred tax assets	15,780	7,597
Deferred tax liabilities
Deferred commissions	(3,215)
Intangible assets	(7,295)	(2,210)
Property and equipment		(190)
Debt discount	(4,986)	(5,679)
Other	(1,233)
Total deferred tax liabilities	(16,729)	(8,079)
Total non-current deferred income tax liabilities	$ (949)	$ (482)