Cover - shares	6 Months Ended
	Jun. 30, 2023	Aug. 04, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-33810
Entity Registrant Name	AMERICAN PUBLIC EDUCATION, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	01-0724376
Entity Address, Address Line One	111 West Congress Street,
Entity Address, City or Town	Charles Town,
Entity Address, State or Province	WV
Entity Address, Postal Zip Code	25414
City Area Code	304
Local Phone Number	724-3700
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	APEI
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		17,774,399
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001201792
Current Fiscal Year End Date	--12-31