XML 88 R81.htm IDEA: XBRL DOCUMENT v3.8.0.1
Concessions and Authorizations - Schedule of Present Value and Nominal Value Portion to be paid (Detail)
R$ in Millions
 12 Months Ended
Dec. 31, 2017
BRL (R$)
Irape enterprise [member]  
Disclosure Of Present Value And Nominal Value Portion To Be Paid [Line Items]  
Percentage interest 100.00%
Amounts paid in 2017 R$ 2
Present value of amounts to be paid in 12 months 2
Nominal value of amounts to be paid in 12 months R$ 2
Queimadao Consortium Enterprise [member]  
Disclosure Of Present Value And Nominal Value Portion To Be Paid [Line Items]  
Percentage interest 82.50%
Amounts paid in 2017 R$ 1
Present value of amounts to be paid in 12 months 1
Nominal value of amounts to be paid in 12 months R$ 1
Salto Morais, Rio de Pedras and Others [member]  
Disclosure Of Present Value And Nominal Value Portion To Be Paid [Line Items]  
Percentage interest 100.00%
Amounts paid in 2017 R$ 1
Present value of amounts to be paid in 12 months 1
Nominal value of amounts to be paid in 12 months R$ 1