Partners' Capital (Changes In Limited Partner Units Outstanding) (Details) - shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Limited Partners' Capital Account [Roll Forward]
Limited partner unitholders, units outstanding		227,068,257	226,679,438	226,200,872
Limited partner unitholders, units outstanding		227,427,247	227,068,257	226,679,438
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		354,529	387,216	476,682
Director [Member]
Limited Partners' Capital Account [Roll Forward]
Partners' Capital Account, Units, Unit-based Compensation	[1]	4,461	1,603	1,884

[1] Limited partner units issued to settle the equity-based retainer paid to independent directors of our general partner.