XML 194 R187.htm IDEA: XBRL DOCUMENT v3.8.0.1
Operating Costs And Expenses - Summary of Other Operating Expenses (Revenues), Net (Detail) - BRL (R$)
R$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Disclosure Of Other Operating Income Expense [Line Items]      
Leasing and rentals R$ 103 R$ 112 R$ 102
Advertising 30 13 11
Subsidies and donations 19 17 31
Paid concession 3 3 7
Insurance 8 9 9
Net loss (gain) on deactivation and disposal of assets 193 112 30
Forluz - Administrative running cost 26 25 22
Collection agents 71 70 71
Loss on investment 9    
Other expenses (34) 420 452
Other operating expenses (revenues), net 383 155 426
Energy [member]      
Disclosure Of Other Operating Income Expense [Line Items]      
Own consumption of energy 24 22 21
CCEE (Electricity Trading Chamber) [member]      
Disclosure Of Other Operating Income Expense [Line Items]      
CCEE annual charge 8 8 R$ 8
Taesa [member]      
Disclosure Of Other Operating Income Expense [Line Items]      
Gain on disposal, Taesa R$ (207) (181)  
Transchile Charrua Transmision SA [Member]      
Disclosure Of Other Operating Income Expense [Line Items]      
Gain on disposal, Transchile   R$ (134)