Earnings Per Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
BASIC EARNINGS PER COMMON UNIT
Net income attributable to common unitholders		$ 1,052.6		$ 1,019.2	$ 3,437.4		$ 3,494.4
Earnings allocated to phantom unit awards	[1]	(7.5)		(6.1)	(24.9)		(21.3)
Net income allocated to common unitholders		$ 1,045.1		$ 1,013.1	$ 3,412.5		$ 3,473.1
Basic weighted-average number of common units outstanding (in units)		2,185.5		2,189.1	2,186.7		2,188.4
Basic earnings per common unit (in dollars per unit)		$ 0.48		$ 0.46	$ 1.56		$ 1.59
DILUTED EARNINGS PER COMMON UNIT
Net income attributable to common unitholders		$ 1,052.6		$ 1,019.2	$ 3,437.4		$ 3,494.4
Diluted weighted-average number of units outstanding:
Common units (in units)		2,185.5		2,189.1	2,186.7		2,188.4
Phantom units (in units)	[2]	15.9		13.2	15.7		13.1
Preferred units (in units)	[2]	0.0	[3]	0.0	0.0	[3]	0.0
Total (in units)		2,201.4		2,202.3	2,202.4		2,201.5
Diluted earnings per common unit (in dollars per unit)		$ 0.48		$ 0.46	$ 1.56		$ 1.59

[1] Phantom units are considered participating securities for purposes of computing basic earnings per unit. See Note 13 for information regarding the phantom units.

[2] We use the “if-converted method” to determine the potential dilutive effect of the vesting of phantom units and the conversion of preferred units outstanding.  See Note 8 for information regarding the preferred units issued on September 30, 2020.  Since the preferred units were issued on the last day of the third quarter of 2020, their weighted-average dilutive impact on earnings per unit for the three and nine months ended September 30, 2020 was negligible. 

[3] * Amount is negligible