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15. CONCESSION CONTRACT ASSETS (Details 1) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Additions | R$ 1,597 |  |
Inflation adjustment | 438 |  |
Results of the Periodic Tariff Review | 552 |  |
Amounts received | (623) |  |
Disposals | (9) |  |
Transfers to financial assets | (60) |  |
Transfers to intangible assets | (906) |  |
Contract assets arising from business combination (Note 16d) | 108 |  |
Impairment | (1) |  |
Ending balance | 4,980 |  |
Restated [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 3,884 | R$ 3,509 |
Effects of IFRS 15 first-time adoption |  | 1,258 | R$ 3,549
Additions |  | 328 | 935
Inflation adjustment |  | (473) | 311
Amounts received |  | (2) | (467)
Disposals |  | (48) |
Transfers to financial assets |  | (685) | (27)
Transfers to intangible assets |  | (3) | (750)
Impairment |  |  | (42)
Ending balance |  | 3,884 | 3,509
Energy Transmission Segment [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 3,076 |  |
Additions | 201 |  |
Inflation adjustment | 438 |  |
Results of the Periodic Tariff Review | 552 |  |
Amounts received | (623) |  |
Disposals | (7) |  |
Contract assets arising from business combination (Note 16d) | 108 |  |
Ending balance | 3,745 | 3,076 |
Energy Transmission Segment [member] | Restated [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 3,076 | 2,909 |
Effects of IFRS 15 first-time adoption |  |  | 2,927
Additions |  | 312 | 138
Inflation adjustment |  | 328 | 311
Amounts received |  | (473) | (467)
Ending balance |  | 3,076 | 2,909
Energy Distribution Segment [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 740 |  |
Additions | 1,346 |  |
Transfers to financial assets | (60) |  |
Transfers to intangible assets | (883) |  |
Impairment | (1) |  |
Ending balance | 1,142 | 740 |
Energy Distribution Segment [member] | Restated [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 740 | 518 |
Effects of IFRS 15 first-time adoption |  |  | 532
Additions |  | 903 | 727
Transfers to financial assets |  |  | (27)
Transfers to intangible assets |  | (48) | (672)
Transfers from PP&E |  | (630) |
Impairment |  | (3) | (42)
Ending balance |  | 740 | 518
Gas Segment [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | 68 |  |
Additions | 50 |  |
Disposals | (2) |  |
Transfers to intangible assets | (23) |  |
Ending balance | 93 | 68 |
Gas Segment [member] | Restated [member] |  |  |
Disclosure of assets recognised from costs to obtain or fulfil contracts with customers [line items] |  |  |
Balance at December 31, 2017 | R$ 68 | 82 |
Effects of IFRS 15 first-time adoption |  |  | 90
Additions |  | 43 | 70
Disposals |  | (2) |
Transfers to intangible assets |  |  | (78)
Transfers from PP&E |  | (55) |
Ending balance |  | R$ 68 | R$ 82

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