SUBSEQUENT EVENTS (Details) $ / shares in Units, $ in Thousands			1 Months Ended			2 Months Ended	3 Months Ended	9 Months Ended
	Oct. 29, 2021 $ / shares shares	Oct. 08, 2021 $ / shares	Nov. 15, 2021 USD ($)	Oct. 31, 2021 USD ($) installment $ / shares shares	Oct. 29, 2021 $ / shares shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 08, 2021 $ / shares
Subsequent Event [Line Items]
Warrant, redemption price (in dollars per share) | $ / shares									$ 0.01
Warrants exercised (in shares)							32,082,532	32,082,532
Warrants exercised, cashless (in shares)							17,015,311	17,015,311
Purchase obligation | $						$ 509,170	$ 509,170	$ 509,170
Public warrants to purchase common stock
Subsequent Event [Line Items]
Warrants exercised (in shares)						32,082,532
Subsequent Event
Subsequent Event [Line Items]
Purchase obligation, term				8 years
Purchase obligation, number of payment installments | installment				5
Purchase obligation | $				$ 148,000
Subsequent Event | Ms. House
Subsequent Event [Line Items]
Annual cash bonuses approved | $			$ 166
Subsequent Event | Mr. Smuts
Subsequent Event [Line Items]
Annual cash bonuses approved | $			81
Subsequent Event | Chief Executive Officer
Subsequent Event [Line Items]
Annual cash bonuses approved | $			400
Subsequent Event | Senior Vice President, Product and Chief Engineer
Subsequent Event [Line Items]
Annual cash bonuses approved | $			282
Subsequent Event | Senior Vice President, Digital
Subsequent Event [Line Items]
Annual cash bonuses approved | $			$ 268
Subsequent Event | Minimum
Subsequent Event [Line Items]
Leases, annual base rent | $				300
Subsequent Event | Maximum
Subsequent Event [Line Items]
Leases, annual base rent | $				$ 600
Subsequent Event | Common Class A
Subsequent Event [Line Items]
Shares repurchased (in shares)				857,825
Shares repurchased, repurchase price (in dollars per share) | $ / shares				$ 24.15
Subsequent Event | Common Class A | Chief Executive Officer
Subsequent Event [Line Items]
Shares repurchased (in shares)				178,796
Subsequent Event | Common Class A | Senior Vice President, Product and Chief Engineer
Subsequent Event [Line Items]
Shares repurchased (in shares)				195,557
Subsequent Event | Common Class A | Senior Vice President, Digital
Subsequent Event [Line Items]
Shares repurchased (in shares)				33,526
Subsequent Event | Common Class A | Director
Subsequent Event [Line Items]
Shares repurchased (in shares)				14,511
Subsequent Event | Public warrants to purchase common stock
Subsequent Event [Line Items]
Warrant, redemption price (in dollars per share) | $ / shares	$ 0.01	$ 0.01			$ 0.01
Warrant, conversion ratio		0.4458
Warrants exercised (in shares)					8,951,665
Warrants exercised, cashless (in shares)	365,803