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Stockholders' Equity - Common stock (Details) - USD ($)			3 Months Ended		9 Months Ended	12 Months Ended
	Jan. 14, 2022	Jun. 16, 2020	Mar. 31, 2022	Mar. 31, 2021	Sep. 30, 2020	Dec. 31, 2021	Apr. 01, 2022	Oct. 23, 2020
Class of Stock [Line Items]
Sale of common stock, net			$ 7,742,000	$ 7,078,000
Proceeds from sale of common stock			7,694,000	7,180,000
Common Stock [Member]
Class of Stock [Line Items]
Sale of common stock, net			$ 6,000	$ 2,000
Common stock issued (in shares)			6,687,610	2,534,879
2020 Purchase Agreement [Member] | Lincoln Park Capital Fund, LLC [Member] | Common Stock [Member]
Class of Stock [Line Items]
Sale of common stock, net					$ 25,000,000.0
Common stock issued (in shares)			5,665,000			5,685,186
Period exercisable from the date of issuance					36 months
Closing price per share		$ 1.05
Proceeds from sale of common stock			$ 7,000,000.0			$ 12,500,000
2020 Purchase Agreement [Member] | Lincoln Park Capital Fund, LLC [Member] | Common Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Remaining common stock issued and sold (in shares)							0
2020 Purchase Agreement [Member] | Lincoln Park Capital Fund, LLC [Member] | Common Stock [Member] | Minimum [Member]
Class of Stock [Line Items]
Percentage issuance of common stock		19.99%
2020 Purchase Agreement [Member] | Lincoln Park Capital Fund, LLC [Member] | Common Stock [Member] | Maximum [Member]
Class of Stock [Line Items]
Common stock issued (in shares)		23,800,000
Sales Agreement [Member] | Canaccord Genuity LLC [Member] | Common Stock [Member] | At The Market Offering Program [Member]
Class of Stock [Line Items]
Remaining availability under financing facility	$ 0							$ 0
Sales Agreement [Member] | Canaccord Genuity LLC [Member] | Common Stock [Member] | Maximum [Member] | At The Market Offering Program [Member]
Class of Stock [Line Items]
Proceeds from sale of common stock	$ 5,000,000
2022 Distribution Agreement [Member] | Canaccord Genuity LLC [Member] | Common Stock [Member]
Class of Stock [Line Items]
Common stock issued (in shares)			1,022,610
Proceeds from sale of common stock			$ 700,000
2020 Distribution Agreement [Member] | Canaccord Genuity LLC [Member] | Common Stock [Member]
Class of Stock [Line Items]
Common stock issued (in shares)						2,179,193
Proceeds from sale of common stock						$ 6,300,000

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