Interest and similar income (Details 1) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue [abstract]
Cash and balances with the Brazilian Central Bank	R$ 5,953,765	R$ 7,315,570	R$ 4,625,467
Loans and advances - Credit institutions	5,107,355	7,472,729	5,075,636
Loans and advances - Customers	44,507,217	43,977,981	41,844,940
Debt instruments	13,456,802	14,783,164	14,872,834
Other interest	2,393,210	3,596,633	3,451,323
Total	R$ 71,418,349	R$ 77,146,077	R$ 69,870,200

The amount of interest income on cash and bank balances at central banks. [Refer: Interest income; Cash and bank balances at central banks]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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The amount of interest income on debt instruments held. [Refer: Interest income; Debt instruments held]

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The amount of interest income on loans and advances to banks. [Refer: Interest income; Loans and advances to banks]

+ References

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The amount of interest income on loans and advances to customers. [Refer: Interest income; Loans and advances to customers]

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The amount of revenue arising from sources that the entity does not separately disclose in the same statement or note. [Refer: Revenue]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The amount of income arising from interest.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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