Stock-Based Compensation - Service Based Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Weighted Average Grant-Date Fair Value
Stock based compensation expenses	$ (179)	$ (236)
Restricted stock units - service based awards
Number of Shares
Unvested at beginning of period (in shares)	29,289	24,136
Granted (in shares)		914
Vested (in shares)		(1,042)
Forfeited (in shares)	(1,223)	(2,396)
Unvested at end of period (in shares)	28,066	21,612
Weighted Average Grant-Date Fair Value
Unvested at beginning of period (in dollars per share)	$ 12.87	$ 28.60
Granted (in dollars per share)		22.99
Vested (in dollars per share)		52.91
Forfeited (in dollars per share)	52.91	27.50
Unvested at end of period (in dollars per share)	$ 11.11	$ 27.39
Stock based compensation expenses	$ 12	$ 104
Unrecognized stock-based compensation expense	$ 100
Unrecognized stock-based compensation expense, weighted average remaining term (in years) (less than)	1 year
Restricted stock units - service based awards \| Minimum
Weighted Average Grant-Date Fair Value
Vesting period	1 year
Restricted stock units - service based awards \| Maximum
Weighted Average Grant-Date Fair Value
Vesting period	3 years

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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