Segment Reporting - Summary Financial Information by Reporting Segment (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenue		$ 145,690	$ 144,986	$ 435,791	$ 453,317
Percentage of total revenue		100.00%	100.00%	100.00%	100.00%
Operating Income (Loss)		$ 19,283	$ 4,539	$ 51,115	$ 23,424
Total Assets	[1]	461,353		461,353		$ 447,096
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Total Assets	[1]	1,662		1,662		1,967
University Group [Member]
Segment Reporting Information [Line Items]
Total revenue		$ 145,619	$ 141,469	$ 435,192	$ 427,176
Percentage of total revenue		100.00%	97.60%	99.90%	94.20%
Operating Income (Loss)		$ 27,331	$ 29,821	$ 84,183	$ 86,636
Total Assets	[1]	140,543		140,543		124,820
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)		(4,362)	(6,199)	(10,904)	(16,595)
Total Assets	[1]	291,894		291,894		291,211
Subtotal [Member]
Segment Reporting Information [Line Items]
Total revenue		$ 145,619	$ 141,469	$ 435,192	$ 427,176
Percentage of total revenue		100.00%	97.60%	99.90%	94.20%
Operating Income (Loss)		$ 22,969	$ 23,622	$ 73,279	$ 70,041
Total Assets	[1]	432,437		432,437		416,031
All Other Campuses [Member]
Segment Reporting Information [Line Items]
Total revenue		$ 71	$ 3,517	$ 599	$ 26,141
Percentage of total revenue		0.00%	2.40%	0.10%	5.80%
Operating Income (Loss)		$ (3,686)	$ (19,083)	$ (22,164)	$ (46,617)
Total Assets	[1]	27,254		27,254		29,098
CTU [Member] | University Group [Member]
Segment Reporting Information [Line Items]
Total revenue		$ 93,115	$ 91,319	$ 280,988	$ 276,558
Percentage of total revenue		63.90%	63.00%	64.50%	61.00%
Operating Income (Loss)		$ 26,261	$ 27,565	$ 80,562	$ 78,649
Total Assets	[1]	76,782		76,782		72,988
AIU [Member] | University Group [Member]
Segment Reporting Information [Line Items]
Total revenue		$ 52,504	$ 50,150	$ 154,204	$ 150,618
Percentage of total revenue		36.00%	34.60%	35.40%	33.20%
Operating Income (Loss)		$ 1,070	$ 2,256	$ 3,621	$ 7,987
Total Assets	[1]	$ 63,761		$ 63,761		$ 51,832

[1] Total assets do not include intercompany receivable or payable activity between schools and corporate and investments in subsidiaries.