Significant Accounting Policies - Tuition Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Tuition receivable	$ 117,146	$ 110,066
Allowance for credit losses	(45,286)	(47,113)
Tuition receivable, net	71,860	62,953
Tuition receivable, noncurrent	2,539	2,673
Other Noncurrent Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Tuition receivable, noncurrent	$ 2,500	$ 2,700