Related Party Transactions - Additional Information (Details)			3 Months Ended					6 Months Ended
	Mar. 29, 2016	Nov. 03, 2014 USD ($)	Jun. 30, 2017 USD ($) credit_facility		Jun. 30, 2016 USD ($)		Mar. 31, 2016	Jun. 30, 2017 USD ($) term credit_facility		Jun. 30, 2016 USD ($)		Dec. 31, 2016	May 23, 2016	May 31, 2015
Related Party Transaction [Line Items]
Aggregate liability of SPLC			$ 10,700,000					$ 10,700,000
Statute of limitations expirations, number of days		60 days
Revenue from related parties			31,500,000	[1]	$ 26,000,000	[2]		60,400,000	[1]	$ 57,900,000	[2]
Gain (loss) from sale of excess allowance oil			100,000		600,000			700,000		500,000
Transportation Services
Related Party Transaction [Line Items]
Revenue from related parties			22,300,000		23,900,000			49,300,000		53,700,000
Storage Services
Related Party Transaction [Line Items]
Revenue from related parties			1,500,000		2,100,000			3,400,000		4,200,000
Transportation Services Operating Leases
Related Party Transaction [Line Items]
Revenue from related parties			$ 7,700,000		0			$ 7,700,000		0
Initial term								10 years
Number of additional terms | term								2
Additional term								5 years
Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Number of credit facilities | credit_facility			3					3
Zydeco, Mars, Bengal, Poseidon and Colonial
Related Party Transaction [Line Items]
Total distributions to general partners			$ 86,700,000		69,300,000			$ 177,700,000		128,800,000
SPLC
Related Party Transaction [Line Items]
General and administrative - related parties			3,100,000		2,900,000			5,000,000		5,400,000
General insurance expense			$ 1,300,000		1,500,000			$ 3,000,000		3,100,000
Five Year Revolver | Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Debt instrument term	5 years						5 years	5 years
Five Year Fixed Facility | Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Debt instrument term								5 years
364 Day Revolver | Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Debt instrument term	364 days						364 days	364 days
SPLC | Zydeco Pipeline Company LLC (“Zydeco”)
Related Party Transaction [Line Items]
Noncontrolling Interest		57.00%	7.50%					7.50%				7.50%	7.50%	37.50%
Maximum
Related Party Transaction [Line Items]
Aggregate liability of SPLC		$ 15,000,000
Shell Pipeline Company L P
Related Party Transaction [Line Items]
Payment of general and administrative fee		$ 8,500,000
Zydeco Pipeline Company LLC (“Zydeco”)
Related Party Transaction [Line Items]
Total distributions to general partners			$ 41,600,000		$ 25,000,000			$ 81,400,000		$ 45,600,000

[1] The 2017 financial information reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

[2] Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.