CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Cash flows from operating activities
Net income	[1]	$ 272.9	[2]	$ 148.9		$ 70.5
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion		21.6	[2]	18.4	[1]	13.7	[1]
Loss (gain) from disposition of fixed assets		0.0	[2]	0.2	[1]	(20.8)	[1]
Allowance oil reduction to net realizable value		1.6	[2]	4.4	[1]
Income in excess of distributions	[3]	(0.6)	[2]	(0.5)	[1]
Changes in operating assets and liabilities
Accounts receivable	[1]			(14.4)		9.5
Allowance oil		(2.8)	[2]	2.4	[1]	0.2	[1]
Prepaid expenses		(1.2)	[2]	(1.5)	[1]	(1.0)	[1]
Accounts payable		(4.5)	[2]	7.6	[1]	0.7	[1]
Deferred revenue		(13.8)	[2]	20.0	[1]
Accrued liabilities		9.5	[2]	(18.5)	[1]	0.6	[1]
Net cash provided by operating activities		282.7	[2]	167.0	[1]	73.4	[1]
Cash flows from investing activities
Capital expenditures		(16.2)	[2]	(68.7)	[1]	(107.3)	[1]
Return of investment	[4]	6.8	[2]	2.1	[1]
(Payment) Receipt of pre-IPO distributions from investments to SPLC		(11.9)	[2]	5.1	[1]
Proceeds from disposition of assets	[1]					22.5
Net cash used in investing activities		(201.1)	[2]	(61.5)	[1]	(84.8)	[1]
Cash flows from financing activities
Borrowings under credit facilities	[2]	458.2
Net proceeds from IPO, net of offering costs of $46.3 million	[1]			1,011.7
Net proceeds from private placement	[2]	297.4
Net proceeds from public offering	[2]	296.8
Contribution from General Partner	[2]	6.1
Other contributions from Parent	[2]	11.1
Proceeds from IPO distributed to Parent	[1]			(911.7)
Capital distributions to General Partner	[2]	(1,002.1)
Distributions to noncontrolling interest		(67.1)	[2]	(25.2)	[1]
Distributions to unitholders and General Partner	[2]	(96.5)
Credit facilities issuance costs		(0.3)	[2]	(0.5)	[1]
Net (distributions to) contributions from Parent		(42.4)	[2]	(27.8)	[1]	11.4	[1]
Distribution of working capital to Parent	[1]			(1.8)
Net cash (used in) provided by financing activities		(138.8)	[2]	44.7	[1]	11.4	[1]
Net (decrease) increase in cash and cash equivalents		(57.2)	[2]	150.2	[1]
Cash at beginning of the year	[1],[2]	150.2
Cash at end of the year	[2]	93.0		150.2	[1]
Non-cash investing and financing transactions:
Change in accrued capital expenditures		2.9	[2]	(13.1)	[1]	$ 19.6	[1]
Contribution of fixed assets from Parent		0.4	[2]	11.4	[1]
Amount payable to SPLC for pre-IPO distribution	[1]			(6.8)
Contribution of investments upon IPO	[1]			$ 166.0
Commencement of capital lease		22.8	[2]				[1]
Other non-cash contributions from Parent	[2]	1.8
Distribution of working capital to the Shell Auger and Lockport Predecessor	[2]	(6.4)
Zydeco
Cash flows from investing activities
2015 Acquisition	[2]	(55.4)
Poseidon
Cash flows from investing activities
2015 Acquisition	[2]	(30.5)
Return of investment	[4]	5.1
Pecten
Cash flows from investing activities
2015 Acquisition	[2]	$ (93.9)

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

[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] Income from equity investments in excess of distributions is shown as a reduction to cash flows from operating activities in our consolidated statements of cash flows.

[4] Distributions received in excess of our income from equity investments is shown as a return of investment in our consolidated statements of cash flows.