Student Receivables - Changes in Current and Non-Current Allowance For Credit Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Balance, Beginning of Period	$ 31,964	$ 24,836	$ 22,534
Beginning balance related to business acquisition	2,174
Provision for credit losses	47,561	43,470	32,042
Amounts written-off	(42,227)	(38,921)	(35,434)
Recoveries	2,675	2,579	5,694
Balance, End of Period	$ 42,147	$ 31,964	$ 24,836