LICENSE, COLLABORATION AND OTHER REVENUE - Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Accounts receivable
Contract assets:
Balance at Beginning of Period	$ 1,901	$ 19,094
Additions	1,426	92,612
Deductions	(2,847)	(109,836)
Balance at End of Period	480	1,870
Prepaid expenses and other current assets
Contract assets:
Balance at Beginning of Period	781	4,309
Additions	0	9,550
Deductions	(781)	(8,250)
Balance at End of Period	0	5,609
Deferred revenue
Contract liability:
Balance at Beginning of Period	47,034	42,380
Additions	0	66,307
Deductions	(3,738)	(64,126)
Balance at End of Period	$ 43,296	44,561
Accounts payable
Contract liability:
Balance at Beginning of Period		3,171
Additions		0
Deductions		(3,171)
Balance at End of Period		$ 0