v3.19.3.a.u2

Acquisitions and divestments - 2017 Divestments (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Nov. 30, 2017 | Jun. 30, 2017 | Dec. 31, 2017
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Selkirk Cogen Partners, LP |  |  |
Divestments |  |  |
Sale of ownership percentage | 17.70% |  |
Proceeds from disposal | $ 1.0 |  |
Equity investment after impairment write down |  | $ 0.0 |
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Selkirk Cogen Partners, LP | Earnings from unconsolidated affiliates |  |  |
Divestments |  |  |
Gain on sale of equity method investment |  |  | $ 1.0
Selkirk Cogen Partners, LP | Earnings from unconsolidated affiliates |  |  |
Divestments |  |  |
Impairment charge on pending sale |  | $ 10.6 | 10.6
Gain on sale of equity method investment |  |  | $ 1.0
Selkirk Cogen Partners, LP | Disposal Group, Disposed of by Sale, Not Discontinued Operations |  |  |
Divestments |  |  |
Sale of ownership percentage | 17.70% |  |

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