LICENSE, COLLABORATION AND OTHER REVENUE - Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Accounts receivable
Contract assets:
Balance at Beginning of Period	$ 1,901	$ 19,094
Additions	943	92,146
Deductions	(2,319)	(54,614)
Balance at End of Period	525	56,626
Prepaid expenses and other current assets
Contract assets:
Balance at Beginning of Period	781	4,309
Additions	0	9,550
Deductions	(781)	(4,309)
Balance at End of Period	0	9,550
Deferred revenue
Contract liability:
Balance at Beginning of Period	47,034	42,380
Additions	0	65,042
Deductions	(3,738)	(59,079)
Balance at End of Period	$ 43,296	48,343
Accounts payable
Contract liability:
Balance at Beginning of Period		3,171
Additions		0
Deductions		(3,171)
Balance at End of Period		$ 0