Summary of Significant Accounting Policies - Net Loss Per Share (Details) - shares	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	49,659,422	7,495,011
Series X Preferred Stock
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	32,545,203
Stock options
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	7,930,334	1,301,262
Warrants for the purchase of common stock
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares)	9,183,885	6,193,749