Stock-Based Compensation - Performance Based Restricted Stock Units (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Weighted Average Grant-Date Fair Value
Stock based compensation expenses	$ 943,000	$ 475,000
Restricted stock units - Performance based awards
Number of Shares
Outstanding at beginning of period (in shares)	0	988,958
Forfeited (in shares)		(988,958)
Outstanding at end of period (in shares)	0	0
Weighted Average Grant-Date Fair Value
Outstanding at beginning of period (in dollars per share)	$ 0	$ 4.48
Forfeited (in dollars per share)		4.48
Outstanding at end of period (in dollars per share)		$ 0
Stock based compensation expenses	$ 0	$ (1,148,000)
Exercisable at end of period	$ 0

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

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