Segment Information - Summary of Financial Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue
Revenue	$ 74,381	$ 67,888	$ 70,560	$ 73,441	$ 76,930	$ 72,992	$ 72,798	$ 74,967	$ 286,270	$ 297,687	$ 299,248
Depreciation and Amortization
Total Depreciation and Amortization									15,596	17,501	18,776
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									12,756	32,526	34,859
Interest Income, Net
Interest income, net									3,908	2,915	185
Income Tax Expense (Benefit)
Total Income Tax Expense									5,187	9,287	11,493
Capital Expenditures
Total Capital Expenditures									7,255	9,430	14,788
American Public Education Segment
Depreciation and Amortization
Total Depreciation and Amortization									14,659	16,175	17,376
Interest Income, Net
Interest income, net									3,866	2,867	185
Income Tax Expense (Benefit)
Total Income Tax Expense									7,754	8,267	10,289
Capital Expenditures
Total Capital Expenditures									6,479	8,793	14,347
Hondros College of Nursing Segment
Depreciation and Amortization
Total Depreciation and Amortization									937	1,326	1,400
Interest Income, Net
Interest income, net									42	48	0
Income Tax Expense (Benefit)
Total Income Tax Expense									(2,567)	1,020	1,204
Capital Expenditures
Total Capital Expenditures									776	637	441
Operating Segments | American Public Education Segment
Revenue
Revenue									256,899	260,062	265,246
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									23,522	28,561	30,873
Operating Segments | Hondros College of Nursing Segment
Revenue
Revenue									29,479	37,625	34,002
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									(10,768)	3,965	3,986
Intersegment elimination
Revenue
Revenue									(108)	0	0
Income from operations before interest income and income taxes
Total income from operations before interest income and income taxes									$ 2	$ 0	$ 0