CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions		Total		Common unitholders - public	Common unitholders - public Shell Pipeline Company L P	Subordinated Units Shell Pipeline Company L P	General Partner Shell Pipeline Company L P	Noncontrolling Interest		Net Parent Investment
Beginning balance at Dec. 31, 2014		$ 1,088.7	[1]	$ 1,016.2	$ (140.3)	$ (440.9)	$ (18.0)	$ 161.4	[1]	$ 510.3	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		374.0	[1],[2],[3]	61.1	24.4	76.6	5.0	73.1	[1]	133.8	[1]
Net proceeds from private placement		297.4	[1]	297.4
Net proceeds from public offerings		296.8	[1]	296.8
Contributions from general partner		6.1	[1]				6.1
Other contributions from Parent		42.6	[1]				12.9			29.7	[1]
Distributions to noncontrolling interest	[1]	(73.2)						(73.2)
Distributions to unitholders and general partner		(96.5)	[1]	(34.0)	(14.5)	(45.5)	(2.5)
Acquisition of noncontrolling interest	[1]	(52.9)						(52.9)
Capital distributions to general partner		(1,002.1)	[1]				(1,002.1)
November 2015 Acquisition	[1]	(93.9)								(93.9)
Net distributions to Parent	[1]	(148.1)								(148.1)
Net assets not contributed to the partnership	[1]	(6.4)								(6.4)
Ending balance at Dec. 31, 2015		632.5	[1]	1,637.5	(130.4)	(409.8)	(998.6)	108.4	[1]	425.4	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		377.5	[1],[2],[3]	107.2	27.2	85.5	25.0	30.3	[1]	102.3	[1]
Net proceeds from public offerings		818.1	[1]	818.1
Contributions from general partner		16.9	[1]				16.9
Other contributions from Parent		9.7	[1]				3.0			6.7	[1]
Distributions to noncontrolling interest	[1]	(30.2)						(30.2)
Distributions to unitholders and general partner		(179.9)	[1]	(77.1)	(20.9)	(65.3)	(16.6)
Acquisition of noncontrolling interest	[1]	(87.0)						(87.0)
Capital distributions to general partner		(903.4)	[1]				(903.4)
Net distributions to Parent	[1]	(120.0)								(120.0)
Ending balance at Dec. 31, 2016		534.2	[1],[4]	2,485.7	(124.1)	(389.6)	(1,873.7)	21.5	[1]	414.4	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		391.8	[1]	118.4	112.3	0.0	64.6	19.2	[1]	77.3	[1]
Net proceeds from public offerings		277.9	[1]	277.9			0.0
Contributions from general partner		5.8	[1]				5.8
Other contributions from Parent		17.1	[1]				17.1			0.0	[1]
Distributions to noncontrolling interest	[1]	(18.9)						(18.9)
Distributions to unitholders and general partner		(267.8)	[1]	(108.5)	(87.1)	(18.7)	(53.5)
November 2015 Acquisition		(1,455.0)	[1]				(1,034.5)			(420.5)	[1]
Net distributions to Parent	[1]	(65.6)								(65.6)
Proceeds from April 2017 divestiture		20.2	[1]				18.7	1.5	[1]
Expiration of subordinated period		0.0	[1]		(408.3)	408.3
Net assets not contributed to the partnership	[1]	(5.6)								(5.6)
Ending balance at Dec. 31, 2017		$ (565.9)	[1]	$ 2,773.5	$ (507.2)	$ 0.0	$ (2,855.5)	$ 23.3	[1]	$ 0.0	[1]

[1] The financial information presented has been retrospectively adjusted for acquisitions of businesses under common control.

[2] The financial information presented has been retrospectively adjusted for acquisitions of businesses under common control.

[3] The financial information presented has been retrospectively adjusted for acquisitions of businesses under common control.

[4] The financial information presented has been retrospectively adjusted for acquisitions of businesses under common control.