Credit Facility and Term Loans - Additional Information (Details)						3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 08, 2021 USD ($) shares	Feb. 08, 2021 USD ($) shares	Feb. 02, 2021 USD ($)	Dec. 01, 2020 USD ($) Installment TradingDay $ / shares shares	Nov. 23, 2018 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Loss on extinguishment of debt						$ (29,772,000)		$ (29,772,000)
Interest expense from credit facility						100,000	$ 600,000	400,000	$ 1,200,000
Expense related to debt issuance costs						100,000	200,000	100,000	400,000
Repaying of term loan								59,500,000
Interest expense						4,802,000	$ 1,084,000	9,552,000	2,217,000
Change in fair value impact of warrant liability						4,387,000		34,589,000
Restricted Stock Awards
Debt Instrument [Line Items]
Loss on extinguishment of debt						4,100,000		4,100,000
February Warrant, Penny Warrant and Additional Warrant
Debt Instrument [Line Items]
Reclassification from a liability to component of equity								80,000,000.0
Private Placement
Debt Instrument [Line Items]
Gross proceeds received	$ 14,800,000
Horizon Term Loan
Debt Instrument [Line Items]
Credit facility maximum borrowing amount											$ 15,000,000.0
Debt instrument maturity month and year											2023-01
Repaying of term loan				$ 15,000,000.0
Interest expense								0.0	1,000,000.0
Amortization of debt issuance costs								0.0	$ 100,000
High Trail Loan December 2020 Note
Debt Instrument [Line Items]
Interest expense										$ 1,100,000
Amortization of debt issuance costs										200,000
Gross proceeds received				38,000,000.0
Aggregate principal amount				$ 43,000,000.0
Number of repayment installments | Installment				24
Line of credit facility, frequency of payments				monthly
Cash payments				$ 1,800,000
Line of credit facility covenant minimum liquidity requirement in unrestricted cash on hand				$ 10,000,000.0
High Trail Loan December 2020 Note | December Warrant
Debt Instrument [Line Items]
Warrants to purchase shares | shares				2,864,133
Warrants to purchase shares, exercise price | $ / shares				$ 9.01
Warrants term				5 years
Warrant exercisable to common stock percentage				200.00%
Warrants consecutive trading days | TradingDay				20
Warrants exercisable date				Jun. 01, 2021
Fair value on issuance				$ 10,500,000
Change in fair value impact of warrant liability										21,300,000
High Trail Loan December 2020 Note | December Warrant | Fair Market Value of Warrant Liability
Debt Instrument [Line Items]
Liabilities										31,800,000
High Trail December 2020 and February 2021 Note
Debt Instrument [Line Items]
Interest expense						300,000		4,100,000
Amortization of debt issuance costs						500,000		500,000
Change in fair value impact of warrant liability						4,400,000		34,600,000
High Trail April 2021 Note
Debt Instrument [Line Items]
Loss on extinguishment of debt						29,700,000		$ 29,700,000
High Trail Amendments
Debt Instrument [Line Items]
Fair value on issuance		$ 10,900,000
Exercise of warrants for common stock shares issued | shares		134,348
High Trail Amendments | Minimum
Debt Instrument [Line Items]
Beneficial ownership limit, percentage		4.99%
High Trail Amendments | Maximum
Debt Instrument [Line Items]
Beneficial ownership limit, percentage		9.99%
Securities Purchase Agreement | High Trail February 2021 Note | 0% Coupon Senior Secured Promissory Note | Investor
Debt Instrument [Line Items]
Aggregate principal amount			$ 16,500,000
Interest rate			0.00%
Maturity date			Feb. 01, 2023
Securities Purchase Agreement | High Trail Loans
Debt Instrument [Line Items]
Cash payments	$ 57,700,000
Securities Purchase Agreement | High Trail Loans | Common Stock
Debt Instrument [Line Items]
Warrants to purchase shares | shares	2,259,166
Securities Purchase Agreement | High Trail Loans | Senior Secured Promissory Notes | Private Placement
Debt Instrument [Line Items]
Aggregate principal amount	$ 110,000,000.0
Interest rate	8.00%
Maturity date	Apr. 08, 2024
High Trail Letter Agreement | December Warrant
Debt Instrument [Line Items]
Exercise of common stock subject to warrant shares | shares		980,000
Payment for exercise of warrant shares		$ 8,800,000
Percent of average daily trading volume		10.00%
High Trail Letter Agreement | Penny Warrant
Debt Instrument [Line Items]
Payment for unexercised portion of warrant		$ 17,000,000.0
High Trail Letter Agreement | Common Stock | December Warrant
Debt Instrument [Line Items]
Warrants to purchase shares | shares		750,000
High Trail Letter Agreement | Common Stock | Penny Warrant
Debt Instrument [Line Items]
Warrants to purchase shares | shares		1,884,133
April Letter Agreement
Debt Instrument [Line Items]
Common stock shares issued | shares	130,000
SPA Amendment
Debt Instrument [Line Items]
Warrant amendment description								The Warrant Amendments amend the February Warrant, the Penny Warrant and the Additional Warrant to amend the definition of “Black Scholes Value” in each warrant to provide that the expected volatility used in the Black Scholes Value shall equal 100% instead of the greater of 100% and the 100-day volatility obtained from the HVT function on Bloomberg (determined utilizing a 365-day annualization factor) as of the trading day immediately following the public announcement of a Change of Control (as defined in each of the warrants), or, if the Change of Control is not publicly announced, the date the Change of Control is consummated.
London Interbank Offered Rate (LIBOR) | Horizon Term Loan
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate											9.90%
Description of variable rate basis											one-month LIBOR
MidCap Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing amount				30,000,000.0	$ 25,000,000.0
Additional increase in borrowing amount				50,000,000.0	$ 50,000,000.0
Line of credit facility, unused capacity, commitment fee percentage					0.50%
Debt offset against and expense over the term					3 years
Line of credit facility, minimum liquidity financial covenant requirement in cash on hand				6,500,000
Line of credit, outstanding						0		$ 0		12,900,000
Available balance of credit facility										$ 1,400,000
Loss on extinguishment of debt						$ (1,500,000)		(1,500,000)
MidCap Credit Facility | Senior Secured Note
Debt Instrument [Line Items]
Aggregate principal amount				$ 43,000,000.0
MidCap Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate					5.75%
Revolving Credit Facility
Debt Instrument [Line Items]
Loss on extinguishment of debt								$ (1,532,000)
Revolving Credit Facility | Terminated Credit Agreement
Debt Instrument [Line Items]
Prepayment fee, percentage	4.30%