Finance and Operating Leases - Lease cost and other information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Finance lease cost:
Amortization of right-of-use assets	$ 7,144	$ 10,018	$ 15,986	$ 19,952
Interest on lease liabilities	466	507	983	895
Total lease cost	11,406	13,479	25,336	27,857
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	(4,968)	(3,361)	(8,587)	(5,966)
Financing cash flows from finance leases	(10,770)	(10,624)	(22,491)	(19,938)
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 8,434	$ 5,305	26,277	25,212
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 625	$ 576
Weighted-average remaining lease term - finance leases	2 years 1 month 13 days	1 year 10 months 2 days	2 years 1 month 13 days	1 year 10 months 2 days
Weighted-average remaining lease term - operating leases	5 years 11 months 15 days	6 years 4 months 6 days	5 years 11 months 15 days	6 years 4 months 6 days
Weighted-average discount rate - finance leases	5.22%	3.31%	5.22%	3.31%
Weighted-average discount rate - operating leases	2.84%	2.77%	2.84%	2.77%
Instructional costs and services
Finance lease cost:
Operating lease cost	$ 2,364	$ 2,640	$ 4,921	$ 6,354
Short-term lease cost	19	31	32	56
Sublease income	(66)	(270)	(197)	(552)
Selling, general and administrative expenses
Finance lease cost:
Operating lease cost	1,546	586	3,745	1,172
Short-term lease cost	56	47	112	140
Sublease income	$ (123)	$ (80)	$ (246)	$ (160)