Property, Equipment and Capitalized Software - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Capitalized software costs, additions	$ 200	$ 1,000
Capitalized software developed for internal use	18,292	23,009
Capitalized software costs, accumulated amortization	700	600
Depreciation and amortization expense	2,537	1,578	$ 1,647
Capitalized Software [Member]
Property Plant And Equipment [Line Items]
Capitalized software costs, disposals	300	0
Capitalized software developed for internal use	1,864	1,960
Depreciation and amortization expense	$ 500	$ 300	$ 200