FAIR VALUE MEASUREMENTS, Changes in Fair Value of Level 3 Warrant Liabilities (Details) - USD ($)	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Warrant Liabilities [Member]
Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance		$ 11,270,000
Transfer to Level 1		(7,350,000)
Change in fair value valuation inputs or other assumptions		400,000
Fair Value, ending balance		7,840,000
Private Placement [Member]
Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance	$ 17,200,000	3,920,000
Transfer to Level 1		0
Change in fair value valuation inputs or other assumptions	(9,920,000)	3,920,000
Fair Value, ending balance	$ 7,280,000	7,840,000
Public Warrants [Member]
Unobservable Input Reconciliation [Roll Forward]
Fair Value, beginning balance		7,350,000
Transfer to Level 1		(7,350,000)
Change in fair value valuation inputs or other assumptions		0
Fair Value, ending balance		$ 0