Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Total Revenue	$ 82,127	$ 70,560	$ 156,743	$ 144,001
Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	80,328	69,182	153,258	141,128
Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	275	274	601	584
Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	1,194	799	2,223	1,661
Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	330	305	661	628
Intersegment
Disaggregation of Revenue [Line Items]
Total Revenue	(22)	(29)	(39)	(56)
Intersegment | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	(22)	(29)	(39)	(56)
Intersegment | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0	0	0
Intersegment | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	0	0	0	0
Intersegment | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0	0	0
APEI | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenue	73,547	63,448	140,641	129,169
APEI | Operating Segments | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	73,082	62,973	139,638	128,171
APEI | Operating Segments | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	275	274	601	584
APEI | Operating Segments | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	0	0	0	0
APEI | Operating Segments | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	190	201	402	414
HCN | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenue	8,602	7,141	16,141	14,888
HCN | Operating Segments | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	7,268	6,238	13,659	13,013
HCN | Operating Segments | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0	0	0
HCN | Operating Segments | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	1,194	799	2,223	1,661
HCN | Operating Segments | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	$ 140	$ 104	$ 259	$ 214