Income Taxes - Schedule of Changes in Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance of unrecognized tax benefits	$ 326	$ 250	$ 167
Additions for current year tax positions	142	65	75
Additions/reductions for prior year tax positions	(14)		0
Ending balance (excluding interest and penalties)	454	315	242
Interest and penalties	15	11	8
Total	$ 469	$ 326	$ 250