Defined Contribution Plan Employee Immediately Vesting Percentage

No definition available.

Name:	apei_DefinedContributionPlanEmployeeImmediatelyVestingPercentage
Namespace Prefix:	apei_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum amount of compensation the entity can withhold annually for contribution into the ESPP.

+ References

No definition available.

+ Details

Name:	apei_EmployeeStockPurchasePlanMaximumAmountOfAnnualCompensationToPurchaseSharesByEligibleParticipants
Namespace Prefix:	apei_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The maximum fair value, as defined, of shares that a participant can purchase each year under the ESPP.

+ References

No definition available.

+ Details

Name:	apei_EmployeeStockPurchasePlanMaximumAnnualFairValueOfSharesPurchasedByParticipant
Namespace Prefix:	apei_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Employee Stock Purchase Plan, Termination Period

+ References

No definition available.

+ Details

Name:	apei_EmployeeStockPurchasePlanTerminationPeriod
Namespace Prefix:	apei_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=apei_AmericanPublicEducationIncEmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Other Employee Benefits - Narrative (Details) - USD ($)		12 Months Ended
Other Employee Benefits - Narrative (Details) - USD ($)	Jun. 13, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of gross annual earnings (up to)		60.00%
Percentage vested in salary reduction contributions		100.00%
Discretionary contributions		$ 3,824,000	$ 3,284,000	$ 3,309,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payroll deduction period (up to)		5 days
Percentage of fair market value		85.00%
Threshold amount of total amount of contributions		$ 21,000
Threshold amount of common stock		$ 25,000
Shares of common stock available		100,000
Common stock available for issuance (in shares)	100,000