Related Party Debt - Additional Information (Details) - USD ($)					3 Months Ended		12 Months Ended
	Mar. 01, 2017	Sep. 27, 2016	Mar. 29, 2016	Aug. 06, 2014	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Nov. 11, 2015	Jun. 29, 2015	May 12, 2015	Nov. 03, 2014
Line Of Credit Facility [Line Items]
Interest and fee expenses					$ 4,000,000	$ 2,100,000
Repayments of debt					$ 0	$ 410,000,000
Revolving Credit Facility | Zydeco
Line Of Credit Facility [Line Items]
Limit on indebtedness				$ 100,000,000.0
Weighted average interest rate					2.60%
Revolving Credit Facility | Zydeco | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity				$ 30,000,000.0
Line of credit facility, expiration period				6 months
Shell Treasury Center West Inc | Five Year Fixed Facility, fixed rate, due March 1, 2022
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Shell Treasury Center West Inc | Five Year Revolver, variable rate, due October 31, 2019
Line Of Credit Facility [Line Items]
Repayments of debt			$ 272,600,000
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity											$ 300,000,000.0
Shell Treasury Center West Inc | Amended And Restated Revolver
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity		$ 760,000,000.0
Issuance fee		600,000
Line of credit facility, increase in maximum borrowing capacity										$ 400,000,000.0
Weighted average interest rate					2.30%
Shell Treasury Center West Inc | Amended And Restated Revolver | Minimum
Line Of Credit Facility [Line Items]
Limit on indebtedness		$ 100,000,000.0
Shell Treasury Center West Inc | 364-Day Revolver, variable rate, due March 1, 2017
Line Of Credit Facility [Line Items]
Repayments of debt			$ 137,400,000
Debt instrument term					364 days		364 days
Line of credit facility maximum borrowing capacity								$ 180,000,000.0
Shell Treasury Center West Inc | 364-Day Revolver, variable rate, due March 1, 2017 | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity									$ 100,000,000.0
Shell Treasury Center West Inc | Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity					$ 600,000,000
Limit on indebtedness	$ 100,000,000.0
Issuance fee	$ 700,000
Fixed interest rate	3.23%
Shell Treasury Center West Inc | Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022 | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	$ 600,000,000.0
Shell Treasury Center West Inc | Revolving Credit Facility | Zydeco
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity					$ 30,000,000
Shell Treasury Center West Inc | Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity					$ 760,000,000.0
Shell Treasury Center West Inc | Revolving Credit Facility | 364-Day Revolver, variable rate, due March 1, 2017
Line Of Credit Facility [Line Items]
Debt instrument term					364 days