Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for receivables
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 6,276	$ 8,077	$ 13,012
Additions/ (Reductions)	4,571	4,671	6,759
Write-offs	(4,199)	(6,472)	(11,694)
Balance at end of period	6,648	6,276	8,077
American Public Education Segment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,253	4,712	10,286
Additions/ (Reductions)	1,937	2,631	4,861
Write-offs	(2,521)	(4,090)	(10,435)
Balance at end of period	2,669	3,253	4,712
Hondros College of Nursing Segment
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	3,023	3,365	2,726
Additions/ (Reductions)	2,634	2,040	1,898
Write-offs	(1,678)	(2,382)	(1,259)
Balance at end of period	$ 3,979	$ 3,023	$ 3,365