Revenue Recognition - Changes in Deferred Revenue Balances (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Deferred Revenue Arrangement [Line Items]
Gross deferred revenue, beginning balance		$ 85,402	$ 63,204
Business acquisitions, beginning balance		5,356	13,395
Revenue earned from prior balances		(74,448)	(65,581)
Billings during period	[1]	710,889	694,681
Revenue earned for new billings during the period		(613,967)	(618,997)
Other adjustments		487	(1,300)
Gross deferred revenue, ending balance		113,719	85,402
University Group [Member] | CTU [Member]
Deferred Revenue Arrangement [Line Items]
Gross deferred revenue, beginning balance		28,522	27,845
Business acquisitions, beginning balance		3,952
Revenue earned from prior balances		(27,857)	(25,179)
Billings during period	[1]	439,836	404,930
Revenue earned for new billings during the period		(378,926)	(378,161)
Other adjustments		(853)	(913)
Gross deferred revenue, ending balance		64,674	28,522
University Group [Member] | AIUS [Member]
Deferred Revenue Arrangement [Line Items]
Gross deferred revenue, beginning balance		56,880	35,359
Business acquisitions, beginning balance		1,404	13,395
Revenue earned from prior balances		(46,591)	(40,402)
Billings during period	[1]	271,053	289,751
Revenue earned for new billings during the period		(235,041)	(240,836)
Other adjustments		1,340	(387)
Gross deferred revenue, ending balance		$ 49,045	$ 56,880

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