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Acquisitions and Investments - Investment in Pipeline Company (Details) bbl / d in Thousands, $ in Millions |  | 3 Months Ended
--- | --- | ---
Feb. 15, 2017 USD ($) Quarterly_reporting_period bbl / d | Mar. 31, 2017 USD ($)
Schedule of Equity Method Investments [Line Items] |  |
IDRs forfeited per quarter | $ 1.6 |
Number of quarters IDRs forfeited | Quarterly_reporting_period | 12 |
Prorated IDRs forfeited |  | $ 0.8
MarEn Bakken |  |
Schedule of Equity Method Investments [Line Items] |  |
Cash paid to acquire equity method investments | $ 500.0 |
Bakken Pipeline System |  |
Schedule of Equity Method Investments [Line Items] |  |
Crude oil throughput | bbl / d | 470 |
MPLX LP | MarEn Bakken |  |
Schedule of Equity Method Investments [Line Items] |  |
Cash paid to acquire equity method investments | $ 500.0 |
Equity method investments, ownership percentage | 25.00% |
MPLX LP | Bakken Pipeline System |  |
Schedule of Equity Method Investments [Line Items] |  |
Equity method investments, ownership percentage | 9.20% |
MPC & Enbridge Energy Partners | MarEn Bakken |  |
Schedule of Equity Method Investments [Line Items] |  |
Cash paid to acquire equity method investments | $ 2,000.0 |
MPC & Enbridge Energy Partners | Bakken Pipeline System |  |
Schedule of Equity Method Investments [Line Items] |  |
Percentage of ownership interest in joint venture acquired | 36.75% |

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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=66011266&loc=d3e33918-111571 + Details
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