Subsequent events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jul. 29, 2022	Jun. 30, 2021	Mar. 31, 2021	Jul. 24, 2022	Jul. 13, 2022	Jun. 30, 2022	Dec. 31, 2021
Subsequent Event [Line Items]
Preferred stock, par value per share						$ 0.001	$ 0.001
Common stock, par value per share						$ 0.001	$ 0.001
Aggregate purchase price		$ 163	$ 150,899
Common Stock [Member]
Subsequent Event [Line Items]
Shares issued and sold		3,000	1,857,000
Aggregate purchase price			$ 2
Subsequent Event [Member] | Series A Preferred Stock [Member] | Change of Control Transactions [Member]
Subsequent Event [Line Items]
Preferred stock, redemption price per share	$ 1,333
Subsequent Event [Member] | Series A Preferred Stock [Member] | Bankruptcy Proceeding [Member]
Subsequent Event [Line Items]
Preferred stock, redemption price per share	1,333
Subsequent Event [Member] | Series A Preferred Stock [Member] | Extension Terms [Member]
Subsequent Event [Line Items]
Preferred stock, redemption price per share	$ 1,333
Financing Agreement Amendment No 12 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Payment in kind amendment fee payable to lender					$ 1,200
Financing Agreement Amendment No 13 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Accrued and unpaid interest payable to lenders				$ 2,900
Subscription Agreement [Member] | Subsequent Event [Member] | Rubric Capital Management LP [Member] | Common Stock [Member] | Private Placement Offering [Member]
Subsequent Event [Line Items]
Shares issued and sold	565,000
Common stock, par value per share	$ 0.001
Purchase price per share	$ 4.72
Aggregate purchase price	$ 2,700
Subscription Agreement [Member] | Subsequent Event [Member] | Series A Preferred Stock [Member] | Rubric Capital Management LP [Member] | Private Placement Offering [Member]
Subsequent Event [Line Items]
Shares issued and sold	15,000
Preferred stock, par value per share	$ 0.001
Purchase price per share	$ 822.21
Aggregate purchase price	$ 12,300
Aggregate gross proceeds	$ 15,000
Preferred stock liquidation preference value per share	$ 1,333
Preferred stock, dividend rate, percentage	25.00%
Financing Agreement Amendment No 16 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Warrants issued to purchase of common stock	185,000
Exercise price of common stock	$ 0.01
Financing Agreement Amendment No 16 [Member] | Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Threshold value of cash proceeds from equity issuance	$ 7,000