STOCKHOLDERS' EQUITY - Stock options (Details) - Common Class D - 2019 Equity and Performance Incentive Plan - Employee Stock Option $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares
Number of Options
Number of Options, Outstanding at Beginning of Year | shares	5,224,136
Number of Options, Grants (in shares) | shares	740,139
Number of Options, Exercised (in shares) | shares	0
Number of Option, Forfeited/cancelled/expired/settled (in shares) | shares	0
Number of Options, Balance at End of Year | shares	5,964,275	5,224,136
Number of Options, Vested and expected to vest (in shares) | shares	5,912,099
Number of Options, Unvested (in shares) | shares	434,342
Number of Options, Exercisable (in shares) | shares	5,529,933
Weighted-Average Exercise Price
Weighted-Average Exercise Price, Outstanding at Beginning of Year (in dollars per share) | $ / shares	$ 2.90
Weighted-Average Exercise Price, Grants (in dollars per share) | $ / shares	3.56
Weighted-Average Exercise Price, Exercised (in dollars per share) | $ / shares	0
Weighted-Average Exercise Price, Forfeited/cancelled/expired/settled (in dollars per share) | $ / shares	0
Weighted-Average Exercise Price, Balance at End of Year (in dollars per share) | $ / shares	2.99	$ 2.90
Weighted-Average Exercise Price, Vested and expected to vest (in dollars per share) | $ / shares	2.97
Weighted-Average Exercise Price, Unvested (in dollars per share) | $ / shares	4.68
Weighted-Average Exercise Price, Exercisable (in dollars per share) | $ / shares	$ 2.85
Weighted-Average Remaining Contractual Term, Outstanding (in years)	5 years 4 months 13 days	5 years 3 months 10 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest (in years)	5 years 4 months 2 days
Weighted-Average Remaining Contractual Term, Unvested (in years)	8 years 8 months 1 day
Weighted-Average Remaining Contractual Term, Exercisable (in years)	5 years 1 month 9 days
Aggregate Intrinsic Value, Outstanding | $	$ 49,770	$ 5,021,952
Aggregate Intrinsic Value, Grants | $	0
Aggregate Intrinsic Value, Exercised | $	0
Aggregate Intrinsic Value, Forfeited/cancelled/expired/settled | $	0
Aggregate Intrinsic Value, Vested and expected to vest | $	49,770
Aggregate Intrinsic Value, Unvested | $	0
Aggregate Intrinsic Value, Exercisable | $	$ 49,770