FAIR VALUE MEASUREMENTS - Fair Value of Financial Instruments, Recurring Basis (Details) - Redeemable convertible preferred stock warrants - Fair Value, Recurring - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants not settleable in cash, fair value disclosure	$ 0	$ 1,331,000
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants not settleable in cash, fair value disclosure		0
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants not settleable in cash, fair value disclosure		0
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants not settleable in cash, fair value disclosure		$ 1,331,000