Leases - Narrative (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) campus	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Property, Plant and Equipment [Line Items]
Variable lease payment	$ 0
Lease expense	2,600,000
APEI Segment
Property, Plant and Equipment [Line Items]
Rent expense	$ 500,000	$ 600,000	$ 700,000
HCN Segment
Property, Plant and Equipment [Line Items]
Number of campuses | campus	5
Rent expense	$ 2,100,000	$ 2,800,000	$ 2,700,000