Fair Value Measurements - Hierarchy for Assets and Liabilities on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Cash and cash equivalents:
Payment-dependent notes receivable, non-current	$ 7,436	$ 5,593
Payment-dependent notes payable, non-current	7,436	5,593
Warrant liabilities	1,958	9,616
Fair Value, Recurring
Cash and cash equivalents:
Term deposits (greater than 90 days)	1,058	7,694
Payment-dependent notes receivable, non-current	7,436	5,593
Total financial assets	78,407	145,640
Payment-dependent notes payable, non-current	7,436	5,593
Total financial liabilities	9,394	15,209
Term deposit, real estate lease agreement obligation	700	1,000
Fair Value, Recurring | December 2023 Warrants
Cash and cash equivalents:
Warrant liabilities	628	4,889
Fair Value, Recurring | Private Placement Warrants
Cash and cash equivalents:
Warrant liabilities	1,330	4,727
Fair Value, Recurring | Money market funds
Cash and cash equivalents:
Money market funds	48,685	130,132
Fair Value, Recurring | U.S. government treasury bills
Cash and cash equivalents:
Money market funds	21,228
Fair Value, Recurring | Term deposits (less than 90 days)
Cash and cash equivalents:
Money market funds		2,221
Fair Value, Recurring | Level 1
Cash and cash equivalents:
Term deposits (greater than 90 days)	0	0
Payment-dependent notes receivable, non-current	0	0
Total financial assets	69,913	130,132
Payment-dependent notes payable, non-current	0	0
Total financial liabilities	0	0
Fair Value, Recurring | Level 1 | December 2023 Warrants
Cash and cash equivalents:
Warrant liabilities	0	0
Fair Value, Recurring | Level 1 | Private Placement Warrants
Cash and cash equivalents:
Warrant liabilities	0	0
Fair Value, Recurring | Level 1 | Money market funds
Cash and cash equivalents:
Money market funds	48,685	130,132
Fair Value, Recurring | Level 1 | U.S. government treasury bills
Cash and cash equivalents:
Money market funds	21,228
Fair Value, Recurring | Level 1 | Term deposits (less than 90 days)
Cash and cash equivalents:
Money market funds		0
Fair Value, Recurring | Level 2
Cash and cash equivalents:
Term deposits (greater than 90 days)	1,058	7,694
Payment-dependent notes receivable, non-current	0	0
Total financial assets	1,058	9,915
Payment-dependent notes payable, non-current	0	0
Total financial liabilities	628	4,889
Fair Value, Recurring | Level 2 | December 2023 Warrants
Cash and cash equivalents:
Warrant liabilities	628	4,889
Fair Value, Recurring | Level 2 | Private Placement Warrants
Cash and cash equivalents:
Warrant liabilities	0	0
Fair Value, Recurring | Level 2 | Money market funds
Cash and cash equivalents:
Money market funds	0	0
Fair Value, Recurring | Level 2 | U.S. government treasury bills
Cash and cash equivalents:
Money market funds	0
Fair Value, Recurring | Level 2 | Term deposits (less than 90 days)
Cash and cash equivalents:
Money market funds		2,221
Fair Value, Recurring | Level 3
Cash and cash equivalents:
Term deposits (greater than 90 days)	0	0
Payment-dependent notes receivable, non-current	7,436	5,593
Total financial assets	7,436	5,593
Payment-dependent notes payable, non-current	7,436	5,593
Total financial liabilities	8,766	10,320
Fair Value, Recurring | Level 3 | December 2023 Warrants
Cash and cash equivalents:
Warrant liabilities	0	0
Fair Value, Recurring | Level 3 | Private Placement Warrants
Cash and cash equivalents:
Warrant liabilities	1,330	4,727
Fair Value, Recurring | Level 3 | Money market funds
Cash and cash equivalents:
Money market funds	0	0
Fair Value, Recurring | Level 3 | U.S. government treasury bills
Cash and cash equivalents:
Money market funds	$ 0
Fair Value, Recurring | Level 3 | Term deposits (less than 90 days)
Cash and cash equivalents:
Money market funds		$ 0