LEASES (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) Squarefeet Option Lease	Mar. 31, 2022 USD ($)	Aug. 31, 2022 USD ($)
Operating Leases [Abstract]
Approximate area of leased school space | Squarefeet	55,000
Undiscounted lease payments	$ 39,148		$ 12,200
Operating lease term	12 years
Number of renewal options | Option	2
Renewal lease term	5 years
Capital expenditures	$ 1,300
Rent paid	200
Operating lease cost	4,900	$ 4,700
Operating cash flow information [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	3,918	4,654
Non-cash activity [Abstract]
Lease liabilities arising from obtaining right-of-use assets	$ 2,142	$ 6,644
Number of new leases | Lease	1
Number of lease modifications | Lease	1
Weighted Average Remaining Lease Term and Discount Rate [Abstract]
Weighted-average remaining lease term	11 years 1 month 24 days	11 years 5 months 4 days
Weighted-average discount rate	6.99%	7.42%
Maturities of Lease Liabilities [Abstract]
2023 (excluding the three months ended March 31, 2023)	$ 12,175
2024	17,373
2025	15,702
2026	13,334
2027	10,053
2028	9,959
Thereafter	61,175
Total lease payments	139,771
Less: imputed interest	(39,148)		$ (12,200)
Present value of lease liabilities	$ 100,623
Minimum [Member]
Operating Leases [Abstract]
Remaining lease term	1 year
Maximum [Member]
Operating Leases [Abstract]
Remaining lease term	19 years
Variable lease cost	$ 100	$ 100