Borrowings - Narrative (Details)				1 Months Ended	6 Months Ended	12 Months Ended
	Jan. 18, 2023 USD ($) trading_day $ / shares	Jul. 29, 2022 USD ($) interest_payment	Jul. 06, 2021 USD ($) trading_day $ / shares	Jan. 31, 2023 USD ($) shares	Jun. 30, 2023 promissoryNote shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Sep. 30, 2023 USD ($)	Dec. 29, 2022 USD ($)	Sep. 30, 2022 USD ($)	Aug. 05, 2022 $ / shares	Sep. 30, 2021
Debt Instrument [Line Items]
Loss on debt extinguishment						$ 3,510,000	$ 942,000
Outstanding amounts						$ 238,962,000	$ 219,744,000
Common stock, par value (in usd per share) | $ / shares	$ 0.0001					$ 0.0001	$ 0.0001				$ 0.0001
Carrying Value						$ 203,859,000	$ 175,831,000
Long-term debt, current						3,332,000	2,872,000
Yorkville Convertible Promissory Note
Debt Instrument [Line Items]
Outstanding amounts						0
Senior Secured Term Loan
Debt Instrument [Line Items]
Carrying Value						85,624,000	81,616,000
Equipment financing facility
Debt Instrument [Line Items]
Carrying Value						5,710,000	8,577,000
Non-cash interest expense						1,111,000	922,000
Remaining borrowing capacity								$ 13,784,000
Long-term line of credit						5,710,000	8,577,000
Long-term debt, current						3,332,000	2,872,000
Related Party
Debt Instrument [Line Items]
Issuance of convertible notes for interest paid-in-kind						36,903,000	10,899,000
Related Party | AFG Convertible Notes
Debt Instrument [Line Items]
Carrying Value						16,623,000
Non-cash interest expense						2,873,000
Nonrelated Party
Debt Instrument [Line Items]
Issuance of convertible notes for interest paid-in-kind						$ 4,972,000	$ 1,886,000
Nonrelated Party | Senior Secured Term Loan | Minimum | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate spread		0.2616%
Nonrelated Party | Senior Secured Term Loan | Minimum | Federal Reserve Bank of New York Financing Rate (NYFRB)
Debt Instrument [Line Items]
Variable rate spread		0.50%
Convertible Notes
Debt Instrument [Line Items]
Issue and sale of shares (in shares) | shares					20,993,417	23,630,937	7,361,602
Convertible Notes | Yorkville Convertible Promissory Note
Debt Instrument [Line Items]
Principal amount									$ 2,000,000
Issue and sale of shares (in shares) | shares				1,953,612
Outstanding amounts						$ 0	$ 2,000,000
Carrying Value						0	2,688,000
Convertible Notes | Embedded Derivatives - Yorkville Convertible Promissory Notes - Related Party
Debt Instrument [Line Items]
Gain (loss) on embedded derivative, net and change member under debt instrument to yorkville convertible promissory note						6,922,000
Convertible Notes | 2021 Convertible Notes Payable
Debt Instrument [Line Items]
Outstanding amounts						115,815,000	109,167,000
Carrying Value						$ 94,386,000	$ 82,950,000
Effective interest rate						40.00%	25.00%
Convertible Notes | AFG Convertible Notes
Debt Instrument [Line Items]
Conversion price per unit (in usd per share) | $ / shares	$ 1.67
Percentage of stock price	130.00%
Threshold trading days | trading_day	20
Consecutive trading days | trading_day	30
Effective interest rate	40.00%					40.00%
Convertible Notes | Related Party
Debt Instrument [Line Items]
Principal amount						$ 35,000,000
Number of additional promissory notes issued | promissoryNote					3
Convertible Notes | Related Party | Yorkville Convertible Promissory Note
Debt Instrument [Line Items]
Amortization of debt discount						17,571,000
Loss on debt extinguishment						3,510,000
Convertible Notes | Related Party | 2021 Convertible Notes Payable
Debt Instrument [Line Items]
Principal amount			$ 100,000,000
Amortization of debt discount						5,237,000	$ 3,588,000
Outstanding amounts						115,815,000	109,167,000
Debt instruments, coupon rate			5.00%
Paid-in-kind interest rate			6.00%
Conversion ratio			49.9910
Conversion price per unit (in usd per share) | $ / shares			$ 20
Percentage of stock price			130.00%
Threshold trading days | trading_day			20
Consecutive trading days | trading_day			30
Redemption percentage			100.00%
Original issue discount			0.50%
Gain (loss) on beneficial conversion feature						840,000	11,488,000
Issuance of convertible notes for interest paid-in-kind						6,648,000
Carrying Value						94,386,000	82,950,000
Non-cash interest expense						12,393,000	10,243,000
Convertible Notes | Related Party | AFG Convertible Notes
Debt Instrument [Line Items]
Principal amount	$ 13,750,000			$ 13,750,000
Amortization of debt discount						743,000
Outstanding amounts						17,429,000
Paid-in-kind interest rate	26500.00%			26.50%
Redemption percentage	100.00%
Carrying Value						18,139,000
Non-cash interest expense						4,631,000
Convertible Notes | Nonrelated Party | AFG Convertible Notes
Debt Instrument [Line Items]
Issuance of convertible notes for interest paid-in-kind						3,679,000
Gain on derivative embedded						2,106,000
Secured Debt | Senior Secured Term Loan
Debt Instrument [Line Items]
Outstanding amounts						100,000,000	100,000,000
Carrying Value						85,624,000	81,616,000
Number of immediately following interest payment required to be escrowed | interest_payment		4
Secured Debt | Nonrelated Party | Senior Secured Term Loan
Debt Instrument [Line Items]
Principal amount		$ 100,000,000
Amortization of debt discount						407,000	142,000
Outstanding amounts						100,000,000	100,000,000
Carrying Value						85,624,000	81,616,000
Non-cash interest expense						17,951,000	6,349,000
Number of days prior to current maturity date		91 days
Minimum prepayment amount		$ 500,000
Repayment applicable treasury rate		0.50%
Escrowed interest						$ 11,755,000
SOFR Loans | Senior Secured Term Loan
Debt Instrument [Line Items]
Effective interest rate						14.15%
SOFR Loans | Nonrelated Party | Senior Secured Term Loan
Debt Instrument [Line Items]
Variable rate spread		8.50%
ABR Loans | Nonrelated Party | Senior Secured Term Loan
Debt Instrument [Line Items]
Debt instruments, coupon rate		7.50%
Line of Credit | Equipment financing facility
Debt Instrument [Line Items]
Outstanding amounts						$ 5,718,000	8,577,000
Carrying Value						$ 5,710,000	$ 8,577,000
Effective interest rate										16.20%		14.30%
Maximum borrowing capacity										$ 25,000