Summary of Significant Accounting Policies - Going Concern and Management's Plans (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Accounting Policies [Abstract]
Net loss	$ (13,324)	$ (25,456)	$ (21,237)	$ (11,870)	$ (3,331)	$ (10,516)	$ (9,984)	$ (8,594)	$ (71,887)	$ (32,425)
Cash and cash equivalents	63,729				118,986				63,729	118,986	$ 80,752
Accumulated deficit	$ (862,956)				$ (791,069)				$ (862,956)	$ (791,069)