Share-Based Compensation - Activity of Service Period Based Stock Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Stock Option Activity, Additional Disclosures
Share price (in dollars per share)	$ 2.46
Service period based stock options
Number of Options
Options Outstanding Beginning Balance (in shares)	9,495
Options Granted (in shares)	1,745
Options Exercised (in shares)	0
Options Forfeited (in shares)	(326)
Options Outstanding Ending Balance (in shares)	10,914	9,495
Weighted Average Exercise Price
Options Outstanding Beginning Balance (in dollars per share)	$ 4.65
Options Granted (in dollars per share)	2.69
Options Exercised (in dollars per share)	0
Options Forfeited (in dollars per share)	4.83
Options Outstanding Ending Balance (in dollars per share)	$ 4.33	$ 4.65
Stock Option Activity, Additional Disclosures
Options Exercisable (in shares)	7,261
Weighted Average Exercise Price, Options Exercisable (in dollars per share)	$ 3.93
Weighted Average Remaining Contractual Term, Options Outstanding	6 years 6 months	6 years 6 months
Weighted Average Remaining Contractual Term, Options Exercisable	5 years
Aggregate Intrinsic Value, Options Outstanding	$ 95	$ 2,452
Aggregate Intrinsic Value, Options Exercisable	$ 95