Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investment Amount	$ 256.8	$ 262.4
Bengal
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Investment Amount	$ 76.7	$ 76.1
Odyssey
Schedule of Equity Method Investments [Line Items]
Ownership	49.00%	49.00%
Investment Amount	$ 3.1	$ 3.0
Mars
Schedule of Equity Method Investments [Line Items]
Ownership	48.60%	48.60%
Investment Amount	$ 128.4	$ 130.2
Poseidon
Schedule of Equity Method Investments [Line Items]
Ownership	36.00%	36.00%
Investment Amount	$ 9.9	$ 13.2
Proteus
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 18.3	$ 19.1
Endymion
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 20.4	$ 20.8

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

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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