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Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
RECENT ACCOUNTING PRONOUNCEMENTS
Collaboration revenue	$ 0	$ 0	$ 0	$ 43,000
Expiration period (in years)			10 years
Asset held for sale		0		0	$ 7,000,000
In-process research and development	$ 0	$ 7,000,000	$ 0	$ 7,000,000
Minimum
RECENT ACCOUNTING PRONOUNCEMENTS
Award vesting period (in years)			1 year
Minimum \| Furniture and fixtures
RECENT ACCOUNTING PRONOUNCEMENTS
Useful life (in years)			3 years
Minimum \| Machinery
RECENT ACCOUNTING PRONOUNCEMENTS
Useful life (in years)			5 years
Maximum
RECENT ACCOUNTING PRONOUNCEMENTS
Award vesting period (in years)			3 years
Maximum \| Furniture and fixtures
RECENT ACCOUNTING PRONOUNCEMENTS
Useful life (in years)			7 years
Maximum \| Machinery
RECENT ACCOUNTING PRONOUNCEMENTS
Useful life (in years)			7 years