Selected Quarterly Financial Data (Unaudited) - Schedule of Quarterly Adjustments to Total Revenues, Income before Income Taxes and Net Income (Details) - USD ($) $ in Millions	3 Months Ended															12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2015	[2]	Dec. 31, 2014		Dec. 31, 2013
Quarterly Financial Information [Line Items]
Total Revenues	$ 84.6	$ 96.2	[1]	$ 79.8	[1]	$ 65.9	[1]	$ 73.3	[1]	$ 63.2	[1]	$ 62.2	[1]	$ 51.6	[1]	$ 326.5		$ 250.3	[3]	$ 147.8	[3]
Income before income taxes	72.4	90.3	[1]	60.8	[1]	49.3	[1]	45.9	[1]	39.1	[1]	40.4	[1]	23.7	[1]	272.8		149.1	[3]	70.6	[3]
Net income	$ 72.5	90.6	[1]	60.7	[1]	49.1	[1]	45.7	[1]	39.1	[1]	40.4	[1]	23.7	[1]	$ 272.9	[3]	148.9	[3]	70.5	[3]
Shell Midstream Partners, L.P.
Quarterly Financial Information [Line Items]
Total Revenues		72.4	[4]	57.6	[4]	51.7	[4]	55.6	[5]	46.9	[5]	43.6	[5]	36.3	[5]			182.4	[6]	94.3	[6]
Income before income taxes		74.1	[4]	45.4	[4]	41.6	[4]	35.8	[5]	31.0	[5]	26.6	[5]	15.2	[5]			108.6	[6]	39.4	[6]
Net income		74.4	[4]	45.3	[4]	41.4	[4]	35.6	[5]	31.0	[5]	26.6	[5]	15.2	[5]			108.4	[6]	39.3	[6]
Shell Auger and Lockport Operations
Quarterly Financial Information [Line Items]
Total Revenues		23.8	[7]	22.2	[7]	14.2	[7]	17.7	[8]	16.3	[8]	18.6	[8]	15.3	[8]			67.9	[9]	53.5	[10]
Income before income taxes		16.2	[7]	15.4	[7]	7.7	[7]	10.1	[8]	8.1	[8]	13.8	[8]	8.5	[8]			40.5	[9]	31.2	[10]
Net income		$ 16.2	[7]	$ 15.4	[7]	$ 7.7	[7]	$ 10.1	[8]	$ 8.1	[8]	$ 13.8	[8]	$ 8.5	[8]			$ 40.5	[9],[11]	$ 31.2	[10],[12]

[1] Information has been retrospectively adjusted to include the Shell Auger and Lockport Operations for periods prior to October 1, 2015.

[2] The 2015 financial information has been retrospectively adjusted for the acquisition of the Shell Auger and Lockport Operations from January 1, 2015 through September 30, 2015.

[3] Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Auger and Lockport Operations.

[4] Includes the consolidated results of the Partnership as previously reported in its 2015 quarterly reports.

[5] Includes the consolidated results of the Partnership as previously reported in its 2014 quarterly reports.

[6] As previously reported in our Annual Report on Form 10-K for 2014.

[7] Results of the Shell Auger and Lockport Operations from January 1, 2015 through September 30, 2015.

[8] Results of the Shell Auger and Lockport Operations for 2014.

[9] Our Predecessors’ results of the Shell Auger and Lockport Operations from January 1, 2014 through December 31, 2014.

[10] Our Predecessor’s results of the Shell Auger and Lockport Operations from January 1, 2013 through December 31, 2013.

[11] Our Predecessors’ cash flows from/to the Shell Auger and Lockport Operations from January 1, 2014 through December 31, 2014.

[12] Our Predecessor’s cash flows from/to the Shell Auger and Lockport Operations from January 1, 2013 through December 31, 2013.