Summary of Stock Option Activity (Parenthetical) (Detail) (USD $)	6 Months Ended
Jul. 28, 2012
Schedule of Share based Compensation Arrangements by Share based Payment Award, Performance Options [Line Items]
Options exercised, exercise price range, lower limit	$ 4.54
Options exercised, exercise price range, upper limit	$ 20.62

Share Based Compensation, Shares Authorized under Stock Option Plans, Exercised in Period, Exercise Price Range, Lower Range Limit

No definition available.

Name:	aeo_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisedInPeriodExercisePriceRangeLowerRangeLimit
Namespace Prefix:	aeo_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration