Stock-based Compensation - Stock Option Award Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, Beginning Balance (in shares)	4,739,940,000
Granted (in shares)	0
Canceled or forfeited (in shares)	(174,187,000)
Exercised (in shares)	0
Outstanding, Ending Balance (in shares)	4,565,753,000	4,739,940,000
Options exercisable (in shares)	1,520,000
Weighted-Average Exercise Price
Beginning Balance (in dollars per share)	$ 5,140
Granted (in dollars per share)
Canceled or forfeited (in dollars per share)	5.63
Exercised (in dollars per share)
Ending Balance (in dollars per share)	5.12	$ 5,140
Options exercisable (in dollars per share)	$ 427.69
Weighted-Average Remaining Contractual Term (years) And Aggregate Intrinsic Value
Options Outstanding, Weighted Average Remaining Contractual Term (years)	9 years 4 months 24 days	9 years 7 months 6 days
Options Exercisable, Weighted Average Remaining Contractual Term (years)	4 years 4 months 24 days
Options Outstanding, Aggregate Intrinsic Value	$ 0	$ 0
Options Exercisable, Aggregate Intrinsic Value	$ 0
Minimum
Weighted-Average Remaining Contractual Term (years) And Aggregate Intrinsic Value
Exercise price of options outstanding (in dollars per share)	$ 4
Maximum
Weighted-Average Remaining Contractual Term (years) And Aggregate Intrinsic Value
Exercise price of options outstanding (in dollars per share)	$ 99,300