Net Income Per Limited Partner Unit (Tables)

9 Months Ended

Sep. 30, 2020

Partners' Capital Notes [Abstract]

Schedule of Distributions Declared, Partners Interest in Partnership Net Income and Net Income per Unit by Class

Net income earned by the Partnership is allocated between the classes of participating securities in accordance with our partnership agreement, after giving effect to priority income allocations to the holders of the preferred units. First, earnings are allocated based on actual cash distributions declared to our unitholders. To the extent net income exceeds or is less than cash distributions declared, this difference is allocated based on the unitholders’ respective ownership percentages, after consideration of any priority allocations of earnings. For the diluted net income per limited partner unit calculation, the preferred units are assumed to be converted at the beginning of the period into common limited partner units on a one-for-one basis, and the distribution formula for available cash in our partnership agreement is recalculated, using the original available cash amount increased only for the preferred distributions which would not have been paid after conversion. 

	Millions of Dollars
	Three Months Ended September 30			Nine Months Ended September 30
	2020		2019	2020	2019
Net income attributable to the Partnership	$	206	237	687	668
Less:
General partners’ distributions declared (including IDRs)*	—		—	—	139
Limited partners’ distributions declared on preferred units*	10		9	29	28
Limited partners’ distributions declared on common units*	200		197	599	409
Distributions less than (more than) net income attributable to the Partnership	$	(4)	31	59	92

*Distributions declared are attributable to the indicated periods.

	Limited Partners’ Common Units		Limited Partners’ Preferred Units	Total
Three Months Ended September 30, 2020
Net income attributable to the Partnership (millions):
Distributions declared	$	200	10	210
Distributions more than net income attributable to the Partnership	(4)		—	(4)
Net income attributable to the Partnership (basic)	196		10	206
Dilutive effect of preferred units	10
Net income attributable to the Partnership (diluted)	$	206
Weighted-average units outstanding—basic	228,340,146
Dilutive effect of preferred units	13,819,791
Weighted-average units outstanding—diluted	242,159,937
Net income attributable to the Partnership per limited partner unit—basic (dollars)	$	0.86
Net income attributable to the Partnership per limited partner unit—diluted (dollars)	0.85

	Limited Partners’ Common Units		Limited Partners’ Preferred Units	Total
Three Months Ended September 30, 2019
Net income attributable to the Partnership (millions):
Distributions declared	$	197	9	206
Distributions less than net income attributable to the Partnership	31		—	31
Net income attributable to the Partnership (basic)	228		9	237
Dilutive effect of preferred units	9
Net income attributable to the Partnership (diluted)	$	237
Weighted-average units outstanding—basic	192,273,672
Dilutive effect of preferred units	13,819,792
Weighted-average units outstanding—diluted	206,093,464
Net income attributable to the Partnership per limited partner unit—basic (dollars)	$	1.18
Net income attributable to the Partnership per limited partner unit—diluted (dollars)	1.15

	Limited Partners’ Common Units		Limited Partners’ Preferred Units	Total
Nine Months Ended September 30, 2020
Net income attributable to the Partnership (millions):
Distributions declared	$	599	29	628
Distributions less than net income attributable to the Partnership	59		—	59
Net income attributable to the Partnership (basic)	658		29	687
Dilutive effect of preferred units	29
Net income attributable to the Partnership (diluted)	$	687
Weighted-average units outstanding—basic	228,330,885
Dilutive effect of preferred units	13,819,791
Weighted-average units outstanding—diluted	242,150,676
Net income attributable to the Partnership per limited partner unit—basic (dollars)	$	2.88
Net income attributable to the Partnership per limited partner unit—diluted (dollars)	2.84

	Limited Partners’ Common Units		General Partner (including IDRs)	Limited Partners’ Preferred Units	Total
Nine Months Ended September 30, 2019
Net income attributable to the Partnership (millions):
Distributions declared	$	409	139	28	576
Distributions less than net income attributable to the Partnership	91		1	—	92
Net income attributable to the Partnership (basic)	500		140	28	668
Dilutive effect of preferred units*	23
Net income attributable to the Partnership (diluted)	$	523
Weighted-average units outstanding—basic	147,367,681
Dilutive effect of preferred units*	13,819,791
Weighted-average units outstanding—diluted	161,187,472
Net income attributable to the Partnership per limited partner unit—basic (dollars)	$	3.39
Net income attributable to the Partnership per limited partner unit—diluted (dollars)	3.25
*The dilutive effect of preferred units assumes the reallocation of net income attributable to the partnership to the limited and general partners, including a reallocation associated with IDRs, pursuant to the available cash formula in the partnership agreement.