MAJOR CUSTOMERS, PARTNERSHIPS AND STRATEGIC ALLIANCES - California Institute for Regenerative Medicine (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2021	May 31, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues			$ 110,701	$ 118,192	$ 102,428
Other non-current liabilities			1,217	7,011
California Institute for Regenerative Medicine ("CIRM")
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Funds due under the agreement		$ 8,000
Other non-current liabilities			$ 0	6,400
Accrued interest				1,200
California Institute for Regenerative Medicine ("CIRM") | Research grants
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	$ 5,200			$ 5,200
Accrued interest	$ 1,200