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GOODWILL (Details) - USD ($) $ in Millions | 1 Months Ended | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jun. 30, 2017 | Sep. 30, 2017 | Sep. 30, 2017
Changes to our goodwill balances by segment |  |  |
Goodwill balance as of January 1, 2017 |  |  | $ 3,046.2
Goodwill balance as of June 30, 2017 |  | $ 3,053.5 | 3,053.5
Accumulated impairment losses |  | 0.0 | 0.0
Amount of Impairment from Goodwill test |  | 0.0 |
Bluewater |  |  |
Changes to our goodwill balances by segment |  |  |
Acquisition of Bluewater | $ 7.3 |  | 7.3
Wisconsin |  |  |
Changes to our goodwill balances by segment |  |  |
Goodwill balance as of January 1, 2017 |  |  | 2,104.3
Goodwill balance as of June 30, 2017 |  | 2,104.3 | 2,104.3
Wisconsin | Bluewater |  |  |
Changes to our goodwill balances by segment |  |  |
Acquisition of Bluewater |  |  | 0.0
Illinois |  |  |
Changes to our goodwill balances by segment |  |  |
Goodwill balance as of January 1, 2017 |  |  | 758.7
Goodwill balance as of June 30, 2017 |  | 758.7 | 758.7
Illinois | Bluewater |  |  |
Changes to our goodwill balances by segment |  |  |
Acquisition of Bluewater |  |  | 0.0
Other States |  |  |
Changes to our goodwill balances by segment |  |  |
Goodwill balance as of January 1, 2017 |  |  | 183.2
Goodwill balance as of June 30, 2017 |  | 183.2 | 183.2
Other States | Bluewater |  |  |
Changes to our goodwill balances by segment |  |  |
Acquisition of Bluewater |  |  | 0.0
Non-Utility Energy Infrastructure |  |  |
Changes to our goodwill balances by segment |  |  |
Goodwill balance as of January 1, 2017 |  |  | 0.0
Goodwill balance as of June 30, 2017 |  | $ 7.3 | 7.3
Non-Utility Energy Infrastructure | Bluewater |  |  |
Changes to our goodwill balances by segment |  |  |
Acquisition of Bluewater |  |  | $ 7.3

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