Summary of Significant Accounting Policies - Foreign Currency (Details)	12 Months Ended
Jan. 31, 2015
Accounting Policies [Abstract]
Prior Period Foreign Currency Exchange Rate, Used to Align Operations Reported	1 month

This element represents the use of prior months' foreign currency exchange rate to align operations reported.

No definition available.

Name:	bby_PriorPeriodForeignCurrencyExchangeRateUsedToAlignOperationsReported
Namespace Prefix:	bby_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration