Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total Revenue	$ 74,616	$ 73,441
Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	72,640	71,946
Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	326	310
Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	1,029	862
Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	621	323
Intersegment
Disaggregation of Revenue [Line Items]
Total Revenue	(17)	(27)
Intersegment | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	(17)	(27)
Intersegment | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0
Intersegment | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	0	0
Intersegment | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0
APEI | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenue	67,094	65,721
APEI | Operating Segments | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	66,556	65,198
APEI | Operating Segments | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	326	310
APEI | Operating Segments | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	0	0
APEI | Operating Segments | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	212	213
HCN | Operating Segments
Disaggregation of Revenue [Line Items]
Total Revenue	7,539	7,747
HCN | Operating Segments | Instructional services, net of grants and scholarships
Disaggregation of Revenue [Line Items]
Total Revenue	6,101	6,775
HCN | Operating Segments | Graduation fees
Disaggregation of Revenue [Line Items]
Total Revenue	0	0
HCN | Operating Segments | Textbook and other course materials
Disaggregation of Revenue [Line Items]
Total Revenue	1,029	862
HCN | Operating Segments | Other fees
Disaggregation of Revenue [Line Items]
Total Revenue	$ 409	$ 110