Segment Reporting and Revenue - Summary of Accrued Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting [Abstract]
Accounts receivable	$ 19,388	$ 15,529
Less: Allowance for doubtful accounts	(165)	(166)	$ (160)	$ (150)
Accounts receivable, net	$ 19,223	$ 15,363