Related Party Transaction - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 01, 2017	Oct. 01, 2017
Related Party Transactions [Abstract]
Net Recovery of short swing profits	$ 100	$ 136
Related legal fees and taxes		200
Cash proceeds provided by financing activities		$ 346

Proceeds from disgorgement of stockholder short swing profits.

No definition available.

Name:	bgfv_ProceedsFromDisgorgementOfStockholderShortSwingProfits
Namespace Prefix:	bgfv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration