SHAREHOLDERS' EQUITY AND PRIVATE WARRANT LIABILITY - Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($) shares	Jan. 04, 2021 USD ($) trading_day $ / shares shares	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) vote trading_day $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Class of Warrant or Right [Line Items]
Common stock, shares authorized (in shares)								1,000,000,000	1,000,000,000
Common stock, par value (in dollars per share) | $ / shares								$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)		12,200,378						12,193,378	6,123,432
Common stock, shares outstanding (in shares)		12,200,378						12,193,378	6,123,432
Number of votes for each share held | vote								1,000
Preferred stock, shares authorized (in shares)								10,000,000	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares								$ 0.0001	$ 0.0001
Preferred stock, shares issued (in shares)								0	0
Preferred stock, shares outstanding (in shares)								0	0
Performance shares (in shares)		300,000
Performance shares, par value (in dollars per share) | $ / shares								$ 0.0001
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, threshold trading day period | trading_day		20
Performance shares, threshold trading days | trading_day		30
Performance shares, stock price trigger (in dollars per share) | $ / shares		$ 15.00
Number of whole shares of common stock entitled to purchase upon exercise of each whole warrant ( in shares)								1
Granted (in shares)									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%
Warrants to purchase common stock outstanding (in shares)								23,873,167,000
Exercise price (in dollars per share) | $ / shares								$ 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
Redemption rights, threshold trading days | trading_day								20
Redemption rights, threshold trading day period | trading_day								30
Liability for private warrants | $	$ 12,850		$ 12,850	$ 18,893	$ 15,836	$ 18,893	$ 12,850	$ 13,614	$ 0
Gain on fair value of private warrant liability | $			6,042	(3,056)	15,003	11,947	17,989	$ 17,225	0
Restatement Adjustments
Class of Warrant or Right [Line Items]
Issuance of common stock as compensation | $			2,409	2,389
Liability for private warrants | $	$ 0		0	0	0	0	0		0
Gain on fair value of private warrant liability | $			$ 0	$ 0	$ 0	$ 0	$ 0		$ 0
Merger Consideration Share Based Compensation Award
Class of Warrant or Right [Line Items]
Granted (in shares)		1,317,035						1,317,035
Fair value | $		$ 19,600
Vesting period		2 years
Share-based compensation expense | $								$ 9,500
Merger Consideration Share Based Compensation Award | Restatement Adjustments
Class of Warrant or Right [Line Items]
Fair value | $		$ 19,600
Vesting period		2 years
Accelerated vesting expense | $		$ 800
Restricted Stock Units (RSUs)
Class of Warrant or Right [Line Items]
Granted (in shares)								707,600
Share-based compensation expense | $								$ 1,000
Public Warrants
Class of Warrant or Right [Line Items]
Warrants to purchase common stock outstanding (in shares)								16,927,389,000
Outstanding warrants exercised (in shares)								1,500
Private Warrants
Class of Warrant or Right [Line Items]
Warrants to purchase common stock outstanding (in shares)								6,945,778,000
Outstanding warrants exercised (in shares)								0
Liability for private warrants | $		$ 30,800
Fair value assumptions, expected term (in years)		5 years						4 years
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						$ 9.21
Fair value assumptions, risk free interest rate (as a percent)		0.38%						1.11%
Fair value assumptions, exercise price, closing price of Public Warrants (in dollars per share) | $ / shares		$ 2.50						$ 1.87
Gain on fair value of private warrant liability | $								$ 17,200
Director
Class of Warrant or Right [Line Items]
Shares issued per director								1,000
Issuance of common stock (in shares)								6,000
Issuance of common stock as compensation | $								$ 53
Director | Restricted Stock Units (RSUs) | Minimum
Class of Warrant or Right [Line Items]
Vesting period								3 years
Director | Restricted Stock Units (RSUs) | Maximum
Class of Warrant or Right [Line Items]
Vesting period								5 years
Grantees Other Than Executives | Restricted Stock Units (RSUs)
Class of Warrant or Right [Line Items]
Granted (in shares)								12,600
Vesting period								3 years
Certain executives | Restricted Stock Units (RSUs)
Class of Warrant or Right [Line Items]
Granted (in shares)	695,000