Provisions for judicial and administrative proceedings, commitments and other provisions (Details 3) R$ in Thousands	Dec. 31, 2018 BRL (R$)
Provisions For Contingent Payments [Abstract]
Balance at beginning of year (in 1/01/2018 after the initial adoption of the IFRS 9)	R$ 674,513
Creation of provision for contingent commitments	(48,246)
Balance at end of year	R$ 626,267

Provisions for contingent payments - Balance at beginning of year (in 1/01/2018 after the initial adoption of the IFRS 9)

No definition available.

Name:	bsbr_ProvisionsForContingentPaymentsBalanceAtBeginningOfYear1012018InAfterTheInitialAdoptionOfTheIFRS9
Namespace Prefix:	bsbr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant