SHAREHOLDERS' EQUITY AND PRIVATE WARRANT LIABILITY (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Jan. 04, 2021 USD ($) trading_day $ / shares shares	Sep. 30, 2021 USD ($) vote $ / shares shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) trading_day vote $ / shares shares	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares
Equity [Abstract]
Common stock, shares authorized (in shares)		1,000,000,000		1,000,000,000		1,000,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001		$ 0.0001
Common stock, shares issued (in shares)		12,206,378		12,206,378		6,123,432
Common stock, shares outstanding (in shares)		12,206,378		12,206,378		6,123,432
Performance shares (in shares)	300,000
Number of votes for each share held | vote		1		1
Performance shares, period post closing date of merger after which shares would be forfeited and cancelled if no Release Event has occurred	7 years
Performance shares, stock price trigger (in dollars per share) | $ / shares	$ 15.00
Performance shares, threshold trading days | trading_day	20
Performance shares, threshold trading day period | trading_day	30
Preferred stock, shares authorized (in shares)		10,000,000		10,000,000		10,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.0001		$ 0.0001		$ 0.0001
Preferred stock, shares outstanding (in shares)		0		0		0
Preferred stock, shares issued (in shares)		0		0		0
Class of Warrant or Right [Line Items]
Issuance of common stock | $		$ 53
Warrants to purchase common stock outstanding (in shares)		23,874,667		23,874,667
Number of whole shares of common stock entitled to purchase upon exercise of each whole warrant ( in shares)		1		1
Exercise price (in dollars per share) | $ / shares		$ 11.50		$ 11.50
Maximum expiration period after completion of merger (in years)				5 years
Redemption rights, stock price trigger (in dollars per share) | $ / shares		$ 24.00		$ 24.00
Redemption rights, threshold trading days | trading_day				20
Redemption rights, threshold trading day period | trading_day				30
Gain on fair value of private warrant liability | $		$ 6,042	$ 0	$ 17,989	$ 0
Liability for private warrants | $		$ 12,850		$ 12,850		$ 0
Maximum number of shares of Common Stock that may be issued pursuant to stock awards under Equity Incentive Plan, percentage of issued and outstanding shares of common stock (as a percent)				10.00%
Director
Class of Warrant or Right [Line Items]
Issuance of common stock (in shares)		1,000
Issuance of common stock | $		$ 53
Restricted Stock Units (RSUs)
Class of Warrant or Right [Line Items]
RSUs granted (in shares)				695,000
Restricted Stock Units (RSUs) | Minimum
Class of Warrant or Right [Line Items]
Vesting period				3 years
Restricted Stock Units (RSUs) | Maximum
Class of Warrant or Right [Line Items]
Vesting period				5 years
Public Warrants
Class of Warrant or Right [Line Items]
Warrants to purchase common stock outstanding (in shares)		16,928,889		16,928,889
Outstanding warrants exercised (in shares)		0		0
Private Warrants
Class of Warrant or Right [Line Items]
Warrants to purchase common stock outstanding (in shares)		6,945,778		6,945,778
Outstanding warrants exercised (in shares)		0		0
Gain on fair value of private warrant liability | $		$ 6,000		$ 18,000
Liability for private warrants | $	$ 30,800
Fair value assumptions, expected term (in years)	5 years			4 years 3 months 18 days
Fair value assumptions, volatility rate (as a percent)	20.00%			35.00%
Fair value assumptions, dividend yield	0.00%			0.00%
Fair value assumptions, underlying stock price (in dollars per share) | $ / shares	$ 14.76	$ 8.90		$ 8.90
Fair value assumptions, risk free interest rate (as a percent)	0.38%			0.81%
Fair value assumptions, exercise price, closing price of Public Warrants (in dollars per share) | $ / shares	$ 2.50	$ 1.49		$ 1.49