CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Common unitholders - public	Common unitholders - public Shell Pipeline Company L P	Common unitholders - public Zydeco Shell Pipeline Company L P	Subordinated Units Shell Pipeline Company L P	Subordinated Units Zydeco Shell Pipeline Company L P	General Partner Shell Pipeline Company L P	General Partner Zydeco Shell Pipeline Company L P	Noncontrolling Interest	Noncontrolling Interest Zydeco	Net Parent Investment	Net Parent Investment Zydeco
Beginning Balance at Dec. 31, 2013	$ 317.2	$ 0.0	$ 0.0		$ 0.0		$ 0.0		$ 0.0		$ 317.2
Net income	148.9	4.5	2.1		6.5		0.3		11.4		124.1
Contribution of fixed assets from the parent	11.4										11.4
Allocation of net parent investment to unitholders - Zydeco				$ 32.2		$ 101.3		$ 4.1		$ 182.5		$ (320.1)
Contribution of ownership interests in equity and cost method investments	166.0		38.9		122.1		5.0
Net proceeds from the IPO, net of offering costs of $46.3 million	1,011.7	1,011.7
Proceeds from the IPO distributed to the parent	(911.7)		(213.5)		(670.8)		(27.4)
Distributions to noncontrolling interest	(32.0)								(32.0)
Distributions to parent	(27.8)										(27.8)
Distribution of working capital to parent	(1.8)										(1.8)
Ending Balance at Dec. 31, 2014	681.9	1,016.2	(140.3)		(440.9)		(18.0)		161.9		103.0
Net income	272.9	61.1	24.4		76.6		5.0		66.5		39.3
Distributions to noncontrolling interest	(67.1)								(67.1)
Net proceeds from private placement	297.4	297.4
Net proceeds from public offerings	296.8	296.8
Contributions from general partner	6.1						6.1
Other contributions from parent	13.3						12.9				0.4
Distributions to unitholders and general partner	(96.5)	(34.0)	(14.5)		(45.5)		(2.5)
Acquisition of noncontrolling interest	(52.9)								(52.9)
Capital distributions to general partner	(1,002.1)						(1,002.1)
November 2015 Acquisition	(93.9)										(93.9)
Distributions to parent	(42.4)										(42.4)
Distribution of working capital to parent	(6.4)										(6.4)
Ending Balance at Dec. 31, 2015	207.1	1,637.5	(130.4)		(409.8)		(998.6)		108.4		0.0
Net income	265.4	107.2	27.2		85.5		25.0		20.5
Distributions to noncontrolling interest	(20.3)								(20.3)
Net proceeds from public offerings	818.1	818.1
Contributions from general partner	16.9						16.9
Other contributions from parent	3.0						3.0
Distributions to unitholders and general partner	(179.9)	(77.1)	(20.9)		(65.3)		(16.6)
Acquisition of noncontrolling interest	(87.0)								(87.0)
Capital distributions to general partner	(903.4)						(903.4)
Ending Balance at Dec. 31, 2016	$ 119.9	$ 2,485.7	$ (124.1)		$ (389.6)		$ (1,873.7)		$ 21.6		$ 0.0