Revenue Recognition - Changes in Deferred Revenue Balances (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Deferred Revenue Arrangement [Line Items]
Business acquisition, beginning balance			$ 13,395
Gross deferred revenue, beginning balance		$ 85,402	63,204
Revenue earned from prior balances		(68,092)	(56,667)
Billings during period	[1]	154,345	149,692
Revenue earned for new billings during the period		(114,739)	(113,727)
Other adjustments		1,106	1,023
Gross deferred revenue, ending balance		58,022	56,920
University Group [Member] | CTU [Member]
Deferred Revenue Arrangement [Line Items]
Gross deferred revenue, beginning balance		28,522	27,845
Revenue earned from prior balances		(25,689)	(25,149)
Billings during period	[1]	101,784	103,044
Revenue earned for new billings during the period		(79,691)	(77,894)
Other adjustments		210	140
Gross deferred revenue, ending balance		25,136	27,986
University Group [Member] | AIU [Member]
Deferred Revenue Arrangement [Line Items]
Business acquisition, beginning balance			13,395
Gross deferred revenue, beginning balance		56,880	35,359
Revenue earned from prior balances		(42,403)	(31,518)
Billings during period	[1]	52,561	46,648
Revenue earned for new billings during the period		(35,048)	(35,833)
Other adjustments		896	883
Gross deferred revenue, ending balance		$ 32,886	$ 28,934

[1] Billings during period includes adjustments for prior billings.