XML 131 R79.htm IDEA: XBRL DOCUMENT v3.19.1
Interbank Deposits and Securities Purchased Under Agreements to Resell - Summary of Interbank Deposits and Securities Purchased Under Agreements to Resell (Parenthetical) (Detail) - BRL (R$)
R$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Disclosure of interbank deposits and securities purchased under agreements to resell [Line Items]    
Amounts pledged in guarantee of operations R$ 5,120 R$ 3,664
Losses (10) (8)
B3 S.A. - Brasil, Bolsa, Balco [Member]    
Disclosure of interbank deposits and securities purchased under agreements to resell [Line Items]    
Amounts pledged in guarantee of operations 5,120  
Amounts pledged in guarantee of repurchase agreement transactions R$ 216,647  
Central Bank [Member]    
Disclosure of interbank deposits and securities purchased under agreements to resell [Line Items]    
Amounts pledged in guarantee of operations   3,664
Amounts pledged in guarantee of repurchase agreement transactions   R$ 185,296