Revenue Recognition - Summary of Disaggregation of Revenue by Major Source (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Total revenue		$ 145,690	$ 144,986	$ 435,791	$ 453,317
Tuition [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		139,534	139,391	417,835	436,012
Technology Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		4,776	4,447	14,131	13,464
Other Miscellaneous Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	572	570	1,770	1,816
Tuition and Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		144,882	144,408	433,736	451,292
Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[2]	808	578	2,055	2,025
University Group [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		145,619	141,469	435,192	427,176
University Group [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		93,115	91,319	280,988	276,558
University Group [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		52,504	50,150	154,204	150,618
University Group [Member] | Tuition [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		89,121	87,603	269,146	265,163
University Group [Member] | Tuition [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		50,349	48,287	148,134	144,942
University Group [Member] | Technology Fees [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		2,823	2,751	8,554	8,313
University Group [Member] | Technology Fees [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		1,953	1,696	5,577	5,151
University Group [Member] | Other Miscellaneous Fees [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	426	466	1,415	1,488
University Group [Member] | Other Miscellaneous Fees [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	145	101	335	306
University Group [Member] | Tuition and Fees [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		92,370	90,820	279,115	274,964
University Group [Member] | Tuition and Fees [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		52,447	50,084	154,046	150,399
University Group [Member] | Other [Member] | CTU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[2]	745	499	1,873	1,594
University Group [Member] | Other [Member] | AIU [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[2]	57	66	158	219
All Other Campuses [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		71	3,517	599	26,141
All Other Campuses [Member] | Tuition [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		64	3,501	555	25,907
All Other Campuses [Member] | Other Miscellaneous Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	1	3	20	22
All Other Campuses [Member] | Tuition and Fees [Member]
Disaggregation Of Revenue [Line Items]
Total revenue		65	3,504	575	25,929
All Other Campuses [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	[2]	$ 6	$ 13	$ 24	$ 212

[1] Other miscellaneous fees include graduation fees, laboratory fees and activity fees.

[2] Other revenue primarily includes contract training revenue and bookstore and laptop sales.