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Provisions - Schedule of Provisions for contingencies (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | R$ 815 | R$ 755 | R$ 755
Additions | 278 | 199 | 117
Reversals | (286) | (46) | (59)
Closed | (129) | (93) | (58)
Other provisions ending balance | 678 | 815 | 755
Labor [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 350 | 290 | 323
Additions | 210 | 125 | 39
Reversals | (4) | (5) | (35)
Closed | (82) | (60) | (37)
Other provisions ending balance | 474 | 350 | 290
Customer relations [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance |  | 18 | 19
Additions |  |  | 14
Reversals |  |  | (2)
Closed |  |  | (13)
Other provisions ending balance |  |  | 18
Other civil actions [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 40 | 28 | 24
Additions | 10 | 18 | 10
Reversals | (2) |  |
Closed | (5) | (6) | (6)
Other provisions ending balance | 43 | 40 | 28
Civil cases [Member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 55 | 46 | 43
Additions | 31 | 33 | 24
Reversals | (4) | (3) | (2)
Closed | (21) | (21) | (19)
Other provisions ending balance | 61 | 55 | 46
Tax [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 68 | 67 | 72
Additions | 9 | 3 | 5
Reversals | (2) | (1) | (9)
Closed | (18) | (1) | (1)
Other provisions ending balance | 57 | 68 | 67
Environment [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance |  |  | 1
Reversals |  |  | (1)
Regulatory [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 44 | 46 | 36
Additions | 15 | 3 | 13
Reversals | (18) | (3) | (3)
Closed | (1) | (2) |
Other provisions ending balance | 40 | 44 | 46
Corporate [Member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 239 | 269 | 239
Additions |  |  | 30
Reversals | (239) | (30) |
Other provisions ending balance |  | 239 | 269
Other [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 59 | 37 | 41
Additions | 13 | 35 | 6
Reversals | (19) | (4) | (9)
Closed | (7) | (9) | (1)
Other provisions ending balance | 46 | 59 | 37
Consumer relations [member] |  |  |
Disclosure of other provisions [line items] |  |  |
Other provisions Beginning Balance | 15 | 18 |
Additions | 21 | 15 |
Reversals | (2) | (3) |
Closed | (16) | (15) |
Other provisions ending balance | R$ 18 | R$ 15 | R$ 18

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- Definition The amount of additional other provisions made. [Refer: Other provisions] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 37 -IssueDate 2017-01-01 -Paragraph 84 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2017-03-01&anchor=para_84_b&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The amount of provisions other than provisions for employee benefits. [Refer: Provisions] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 37 -IssueDate 2017-01-01 -Paragraph 84 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2017-03-01&anchor=para_84_a&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 78 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_78_d&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The amount reversed for unused other provisions. [Refer: Other provisions] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 37 -IssueDate 2017-01-01 -Paragraph 84 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2017-03-01&anchor=para_84_d&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition Closed provisions other provisions. + References No definition available. + Details
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