Revenue Recognition - Summary of Disaggregation of Revenue by Major Source (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue		$ 173,998	$ 169,126	$ 533,175	$ 516,155
University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	104,788	98,985	312,645	302,766
University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[2]	68,948	70,048	219,648	213,279
Corporate and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[3],[4]	262	93	882	110
Tuition [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		163,831	160,465	503,780	489,769
Tuition [Member] | University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		98,730	93,071	294,058	284,826
Tuition [Member] | University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		65,101	67,394	209,722	204,943
Technology Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		8,301	7,524	24,982	23,096
Technology Fees [Member] | University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		5,339	5,085	16,352	15,367
Technology Fees [Member] | University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		2,962	2,439	8,630	7,729
Other Miscellaneous Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[5]	463	482	1,468	1,499
Other Miscellaneous Fees [Member] | University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[5]	278	290	959	985
Other Miscellaneous Fees [Member] | University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[5]	185	192	509	514
Tuition and Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		172,595	168,471	530,230	514,364
Tuition and Fees [Member] | University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		104,347	98,446	311,369	301,178
Tuition and Fees [Member] | University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		68,248	70,025	218,861	213,186
Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[6]	1,403	655	2,945	1,791
Other [Member] | University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[6]	441	539	1,276	1,588
Other [Member] | University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[6]	700	23	787	93
Other [Member] | Corporate and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[4],[6]	$ 262	$ 93	$ 882	$ 110

[1] CTU results of operations and total assets include the Hippo acquisition commencing on the September 10, 2021 date of acquisition and as of September 30, 2021.

[2] AIU results of operations and total assets include the DigitalCrafts acquisition commencing on the August 2, 2021 date of acquisition and as of September 30, 2021. AIU’s results of operations include Trident from the March 2, 2020 date of acquisition.

[3] Corporate and Other includes results of operations and total assets for closed campuses. Revenue recorded within Corporate and Other relates to miscellaneous non-student related revenue.

[4] Revenue recorded within Corporate and Other relates to miscellaneous non-student related revenue.

[5] Other miscellaneous fees include student activity fees and graduation fees.

[6] Other revenue primarily includes contract training revenue and miscellaneous non-student related revenue.