This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Equity method investments in unconsolidated affiliates - impairments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended		30 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017
Equity in earnings of unconsolidated affiliates
Equity in (loss) earnings of unconsolidated affiliates	$ (54.4)	$ 7.6	$ (45.4)	$ 18.3
Equity Method Investments.	204.2		204.2		$ 266.8		$ 204.2
Distributions from unconsolidated affiliates	$ 13.5	$ 19.2	$ 17.2	$ 23.5
Chambers Cogen, LP
Equity in earnings of unconsolidated affiliates
Percentage of ownership interest	40.00%		40.00%				40.00%
Equity in (loss) earnings of unconsolidated affiliates			$ 3.4		$ 5.5	$ 6.5
Equity impairment other than temporary	$ 47.1
Equity Method Investments.	124.0		124.0				$ 124.0
Distributions from unconsolidated affiliates							33.6
Estimated fair value of equity investment	$ 77.2		$ 77.2				$ 77.2
Selkirk Cogen Partners LP
Equity in earnings of unconsolidated affiliates
Percentage of ownership interest	17.70%		17.70%				17.70%
Equity in (loss) earnings of unconsolidated affiliates			$ 1.2
Equity impairment other than temporary	$ 10.6