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20. INTANGIBLE ASSETS (Details 1) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | R$ 10,777 |  | R$ 11,156 |  | R$ 10,820 |
Assets arising from business combination |  |  |  | 166 |  |  |
Additions |  | 934 |  | 34 |  | 1,105 |
Disposals |  | (41) |  | (27) | [1] | (19) |
Effects of first-time adoption of IFRS 15 |  |  |  | (621) |  |  |
Amortization |  | (704) |  | (675) |  | (646) |
Transfer to Held for sale |  |  |  | (7) |  |  |
Transfer |  | 658 |  | 751 | [2] | (104) | [3]
Ending balance |  | 11,624 |  | 10,777 |  | 11,156 |
Intangible Assets Under Development [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 63 |  | 686 |  | 1,535 |
Additions |  | 36 |  | 33 |  | 1,105 |
Disposals |  |  |  | (4) |  | (8) |
Effects of first-time adoption of IFRS 15 |  |  |  | (621) |  |  |
Transfer |  | (17) | [2] | (31) |  | (1,946) | [3]
Ending balance |  | 82 |  | 63 |  | 686 |
Temporary Easements Intangible Assets [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 8 |  | 10 |  | 10 |
Amortization |  | (1) |  | (1) |  |  |
Ending balance |  | 8 |  | 8 |  | 10 |
Onerous Concession [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 7 |  | 8 |  | 9 |
Amortization |  |  |  | (1) |  | (1) |
Ending balance |  | 7 |  | 7 |  | 8 |
Assets Of Concession [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 10,680 | [4] | 10,435 |  | 9,248 |
Assets arising from business combination |  |  |  | 162 |  |  |
Additions |  | 891 |  |  |  |  |
Disposals |  | (41) | [1] | (23) |  | (11) |
Amortization |  | (698) |  | (668) |  | (638) |
Transfer |  | 685 | [2] | 774 |  | 1,842 | [3]
Ending balance |  | 11,517 | [4] | 10,680 | [4] | 10,435 |
Other Intangible Assets [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 19 |  | 17 |  | 18 |
Assets arising from business combination |  |  |  | 4 |  |  |
Additions |  | 7 |  | 1 |  |  |
Disposals | [1] | (5) |  |  |  |  |
Amortization |  |  |  | (5) |  | (7) |
Transfer to Held for sale |  |  |  | (7) |  |  |
Transfer |  | (10) | [2] | 8 |  | 6 | [3]
Ending balance |  | 10 |  | 19 |  | 17 |
Useful Life Defined Intangible Asset [Member] |  |  |  |  |  |  |
Disclosure of detailed information about intangible assets [line items] |  |  |  |  |  |  |
Beginning balance |  | 10,714 |  | 11,156 |  | 9,285 |
Assets arising from business combination |  |  |  | 166 |  |  |
Additions |  | 898 |  | 1 |  |  |
Disposals |  | (41) | [1] | (23) |  | (11) |
Amortization |  | (704) |  | (675) |  | (646) |
Transfer to Held for sale |  |  |  | (7) |  |  |
Transfer |  | 675 | [2] | 782 |  | 1,842 | [3]
Ending balance |  | R$ 11,542 |  | R$ 10,714 |  | R$ 11,156 |
[1] | This includes the impairment, in the amount of R$ 22 recognized in the Income Statement under "Other expenses". The test of impairment of intangible assets, relating to the authorization for wind power generation granted to Volta do Rio, recognized in 2018 as part of the its business combination, arises from non- achievement of the operational performance expected in 2019 for the wind generation assets of the subsidiary. The Value in Use of the assets was calculated based on the projection of future expected cash flows for the operation of the assets of the subsidiary, brought to present value by the weighted average cost of capital defined for the company's activity, using the Firm Cash Flow (FCFF) methodology.
[2] | The transfers were made between Intangible assets, concession contract assets and property, plant and equipment are as follows: (1) R$685 from concession contract assets to intangible assets; (2) (R$4) from intangible assets to property, plant and equipment and; and (3) (R$23) from intangible assets to concession financial assets.
[3] | Balances transferred to financial assets.
[4] | The rights of authorization to generate wind power granted to the subsidiary Parajuru and Volta do Rio, valued at R$ 127, and of the gas distribution concession, granted to Gasmig, valued at R$ 426, are classified in the consolidated statement of financial position under intangibles assets and are amortized by the straight-line method, for the period of the concessions.

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