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
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-Name Accounting Standards Codification
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-Section 50
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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
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The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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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.

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No definition available.

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- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

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Acquisitions and Dispositions - Investment Acquisition (Details) - USD ($) shares in Millions, $ in Millions	Apr. 03, 2017	Mar. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity method investment		$ 2,469.0	$ 2,343.0
Subsequent Event \| Advantage
Schedule of Equity Method Investments [Line Items]
Cash consideration	$ 26.0
Ownership percentage	50.00%
Equity method investment	$ 66.5
Advantage Joint Venture \| Subsequent Event \| Advantage
Schedule of Equity Method Investments [Line Items]
Cash consideration	$ 133.0
PAA \| Common Units \| Subsequent Event \| Advantage
Schedule of Equity Method Investments [Line Items]
Contribution of common units (units)	1.3