v3.20.1

Partners' Capital and Distributions (Changes In Limited Partner Units Outstanding) (Details) - shares | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Limited Partners' Capital Account [Roll Forward] |  |  |
Limited partner unitholders, units outstanding (in shares) | 228,195,160 | 228,024,556 | 227,783,916
Partners' Capital Account, Units, Unit-based Compensation (in shares) | 199,792 | 168,913 | 216,679
Limited partner unitholders, units outstanding (in shares) | 228,403,428 | 228,195,160 | 228,024,556
Limited Partners' Capital Account, Right to Receive Distribution in Cash, Period | 45 days |  |
Limited Partners' Capital Account, Removal of Magellan GP, LLC, Percentage Vote | 100.00% |  |
Limited Partners' Capital Account, Annual Report Available, Period | 120 days |  |
Limited Partners' Capital Account, Tax Reporting Information, Period | 90 days |  |
Management [Member] |  |  |
Limited Partners' Capital Account [Roll Forward] |  |  |
Partners' Capital Account, Units, Unit-based Compensation (in shares) | 199,792 | 168,913 | 216,679
Director [Member] |  |  |
Limited Partners' Capital Account [Roll Forward] |  |  |
Partners' Capital Account, Units, Unit-based Compensation (in shares) | 8,476 | 1,691 | 23,961

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