Credit Facility and Term Loans - Additional Information (Details)										3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 22, 2021 USD ($) TradingDay $ / shares shares	Aug. 19, 2021 USD ($)	Aug. 09, 2021 USD ($) $ / shares shares	Jun. 15, 2021	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 ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)	Oct. 21, 2021 shares	Sep. 23, 2021 shares	Aug. 11, 2021 USD ($)
Debt Instrument [Line Items]
Loss on extinguishment										$ 106,991,000			$ 136,763,000
Interest expense from credit facility										0.0	$ 400,000		400,000	$ 1,600,000
Expense related to debt issuance costs										0.0	200,000		100,000	500,000
Interest expense										2,919,000	960,000		12,470,000	3,177,000
Common stock shares issued | shares			2,666,667
Accounts receivable, net			$ 65,000,000.0
Cash and cash equivalents										37,470,000	$ 37,385,000		37,470,000	37,385,000
Warrants exercise period after resale				60 days
Change in fair value impact of warrant liability										(8,134,000)			26,455,000
Minimum
Debt Instrument [Line Items]
Increase minimum cash threshold covenant			15,000,000.0
Cash and cash equivalents			30,000,000
Maximum
Debt Instrument [Line Items]
Increase minimum cash threshold covenant			30,000,000.0
Restricted Stock Awards
Debt Instrument [Line Items]
Loss on extinguishment													4,100,000
February Warrant, Penny Warrant and Additional Warrant
Debt Instrument [Line Items]
Reclassification from a liability to component of equity						$ 21,300,000						$ 80,000,000.0	21,300,000
February, Penny and Additional warrants
Debt Instrument [Line Items]
Change in fair value impact of warrant liability	$ 17,400,000
High Trail Warrants | Subsequent Event
Debt Instrument [Line Items]
Common stock shares issued | shares																	3,479,097
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	1,500,000
Amortization of debt issuance costs													0.0	$ 400,000
High Trail Loan December 2020 Note
Debt Instrument [Line Items]
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
Warrant exercisable to common stock percentage								200.00%
Warrants consecutive trading days | TradingDay								20
Warrants to purchase shares, exercise price | $ / shares								$ 9.01
Warrants term								5 years
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 April 2021 Note
Debt Instrument [Line Items]
Loss on extinguishment										28,200,000			28,200,000
Repaying of term loan													$ 10,139,000
Event of default description													On August 9, 2021, pursuant to those certain Letter Agreements entered into between the Company and High Trail with respect to each of the April 2021 Notes (collectively, the “August Letter Agreements”), High Trail notified the Company that High Trail declared an event of default under the April 2021 Notes as a result of the Company’s Adjusted EBITDA (as defined in the April 2021 Notes) not being equal to at least $12 million for the 12 month period ended June 30, 2021 and further notified the Company that High Trail immediately accelerated a total of $18.7 million of the principal amount of the April 2021 Notes, requiring the Company to immediately pay $21.5 million (such amount equal to 115% of the principal amount that was accelerated, as required under the terms of the April 2021 Notes, plus $0.3 million of accrued but unpaid interest on the principal amount that was accelerated) (the “Current Event of Default Acceleration Amount”)
Accelerated principal amount			18,700,000
Debt instrument redemption amount			$ 21,500,000
Debt instrument redemption price percentage			115.00%
Accrued, Unpaid interest			$ 300,000
Base percentage used to calculate current event of default acceleration			0.80
Description of current event of default acceleration payment													Pursuant to the August Letter Agreements, the Company agreed, among other things, to pay the Current Event of Default Acceleration Amount in cash by August 9, 2021 and that any portion not paid in cash would be paid in shares of the Company’s common stock under the terms of the April 2021 Notes, with the number of shares issuable equal to the unpaid Current Event of Default Acceleration Amount divided by 80% of the lesser of (i) the Daily VWAP (as defined in the April 2021 Notes) on August 9, 2021 and (ii) the average of the lowest two (2) Daily VWAPs during the ten (10) day VWAP trading period ending on August 9, 2021.
High Trail April 2021 Note | Minimum
Debt Instrument [Line Items]
Debt instrument default amount			$ 12,000,000
High Trail
Debt Instrument [Line Items]
Maturity date	Apr. 01, 2023
Accelerated principal amount	$ 66,300,000
Debt instrument redemption amount	$ 76,900,000
Debt instrument redemption price percentage	115.00%
Accrued, Unpaid interest	$ 300,000
Base percentage used to calculate current event of default acceleration	0.80
Warrant exercisable to common stock percentage	200.00%
Warrants consecutive trading days | TradingDay	20
Warrants to purchase shares, exercise price | $ / shares	$ 0.01
Common stock issued subject to satisfy obligation to repay acceleration amount | shares	3,474,814																	5,838,096
Notes extinguished in exchange for debt repayment	$ 25,000,000.0
Extinguishment of debt										107,000,000.0
High Trail | High Trail Debt Repayment
Debt Instrument [Line Items]
Loss on extinguishment													$ 107,000,000.0
High Trail | High Trail April 2021 Notes Repayment
Debt Instrument [Line Items]
Loss on extinguishment													28,200,000
High Trail | Credit Facility
Debt Instrument [Line Items]
Loss on extinguishment													$ 1,500,000
High Trail | Minimum
Debt Instrument [Line Items]
Increase minimum cash threshold covenant	$ 15,000,000.0
Beneficial ownership limit, percentage	9.99%
High Trail | Maximum
Debt Instrument [Line Items]
Increase minimum cash threshold covenant	$ 30,000,000.0
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%
High Trail December 2020 and February 2021 Note
Debt Instrument [Line Items]
Change in fair value impact of warrant liability		$ (8,100,000)
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
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 amended 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.
Letter Agreements | High Trail April 2021 Notes
Debt Instrument [Line Items]
Base percentage used to calculate current event of default acceleration			0.80
Payment in cash of current event of default acceleration amount			$ 10,100,000
Payment in shares of current event of default acceleration amount			$ 11,700,000																$ 11,700,000
Payment in shares of current event of default acceleration shares | shares			2,841,251
Share price | $ / shares			$ 4.1007
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
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										$ 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													$ 1,532,000
Revolving Credit Facility | Terminated Credit Agreement
Debt Instrument [Line Items]
Prepayment fee, percentage					4.30%