Gift Card Liability and Loyalty Program Included in Accrued Expenses on Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 29, 2022	Dec. 28, 2021
Contract With Customer Asset And Liability [Abstract]
Gift card liability	$ 15,078	$ 19,499
Deferred loyalty revenue	$ 3,848	$ 3,949

Contract with customer liability for unredeeemed gift cards.

No definition available.

Name:	bjri_ContractWithCustomerLiabilityForUnredeeemedGiftCards
Namespace Prefix:	bjri_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant