Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Jul. 01, 2015
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 262.4	$ 185.0
Bengal
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 76.1	$ 75.6
Equity method investment percentage	50.00%	49.00%
Unamortized negative basis difference	$ 5.9	$ 6.0
Odyssey
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 3.0	$ 0.0
Equity method investment percentage	49.00%	0.00%
Unamortized negative basis difference	$ 0.8
Mars
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 130.2	$ 84.0
Equity method investment percentage	48.60%	28.60%
Unamortized positive basis difference	$ 17.3	$ 11.1
Poseidon
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 13.2	$ 25.4
Equity method investment percentage	36.00%	36.00%	36.00%
Unamortized positive basis difference	$ 9.4	$ 10.3
Proteus
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 19.1	$ 0.0
Equity method investment percentage	10.00%	0.00%
Unamortized positive basis difference	$ 4.5
Endymion
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 20.8	$ 0.0
Equity method investment percentage	10.00%	0.00%
Unamortized positive basis difference	$ 6.4

Equity Method Investments, Gain From Contribution

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- Definition

Difference between amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and amount of underlying equity in net assets the reporting Entity has in the investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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