Notes Payable, Preferred Stock and Stock Purchase Warrants - Term Notes Payable (Details)	1 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended
	Jul. 31, 2019 USD ($) $ / shares	Mar. 31, 2018 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) shares
Long term debt
Loss on extinguishment of debt and issuance of debt				$ (3,183,000)
2023 Notes.
Long term debt
Fair value of the embedded conversion option			$ 400,000		$ 5,800,000
2023 Notes
Long term debt
Principal amount		$ 53,000,000.0	15,700,000		15,700,000
Conversion rate (per $1,000 of principal)		294.1176
Conversion price (in dollars per share) | $ / shares		$ 3.40
Repurchase price as a percent of principal amount		100.00%
Transaction costs		$ 2,200,000
Amortization percent		9.30%
Repurchase amount	$ 37,000,000.0
Amount of principal which is converted to shares		$ 1,000
Original debt conversion amount			0
2025 Notes.
Long term debt
Principal amount	$ 82,000,000.0		51,199,000		51,199,000
Conversion rate (per $1,000 of principal)	757.5758
Conversion price (in dollars per share) | $ / shares	$ 1.32
Amount of principal which is converted to shares	$ 1,000
Original debt conversion amount			$ 0		$ 6,500,000
Debt converted, Shares issued | shares					4,924,998
Loss on extinguishment of debt and issuance of debt				$ (3,183,000)	$ (3,200,000)