FAIR VALUE MEASUREMENTS - Schedule of Assets and Liabilities on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets, Fair Value Disclosure [Abstract]
Total assets	$ 211,444	$ 238,022
Liabilities, Fair Value Disclosure [Abstract]
Earnout warrant liabilities	636
Earnout warrant liabilities		1,476
Total liabilities	12,493	28,997
Public common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	8,042	18,666
Private common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	3,815	8,855
Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	211,369	237,897
Certificate of deposit
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	75	125
Level 1
Assets, Fair Value Disclosure [Abstract]
Total assets	211,369	237,897
Liabilities, Fair Value Disclosure [Abstract]
Earnout warrant liabilities	0
Earnout warrant liabilities		0
Total liabilities	8,042	18,666
Level 1 | Public common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	8,042	18,666
Level 1 | Private common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	0	0
Level 1 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	211,369	237,897
Level 1 | Certificate of deposit
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	0	0
Level 2
Assets, Fair Value Disclosure [Abstract]
Total assets	75	125
Liabilities, Fair Value Disclosure [Abstract]
Earnout warrant liabilities	636
Earnout warrant liabilities		1,476
Total liabilities	4,451	10,331
Level 2 | Public common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	0	0
Level 2 | Private common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	3,815	8,855
Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	0	0
Level 2 | Certificate of deposit
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	75	125
Level 3
Assets, Fair Value Disclosure [Abstract]
Total assets	0	0
Liabilities, Fair Value Disclosure [Abstract]
Earnout warrant liabilities	0
Earnout warrant liabilities		0
Total liabilities	0	0
Level 3 | Public common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	0	0
Level 3 | Private common stock warrants
Liabilities, Fair Value Disclosure [Abstract]
Common stock warrants	0	0
Level 3 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	0	0
Level 3 | Certificate of deposit
Assets, Fair Value Disclosure [Abstract]
Cash equivalents and restricted cash:	$ 0	$ 0