UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net income	$ 402.0	$ 335.0
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion	36.0	34.0
Loss from revision of asset retirement obligation	2.0	0.0
Allowance oil reduction to net realizable value	1.0	0.0
Non-cash interest expense	1.0	0.0
Undistributed equity earnings	(5.0)	(2.0)
Changes in operating assets and liabilities
Accounts receivable	4.0	(13.0)
Allowance oil	(1.0)	(3.0)
Prepaid expenses and other assets	14.0	10.0
Accounts payable	0.0	(5.0)
Deferred revenue and other unearned income	(11.0)	(4.0)
Accrued liabilities	15.0	16.0
Net cash provided by operating activities	458.0	368.0
Cash flows from investing activities
Capital expenditures	(31.0)	(38.0)
Acquisitions from Parent	(90.0)	(482.0)
Contributions to investment	(13.0)	(21.0)
Return of investment	56.0	41.0
Net cash used in investing activities	(78.0)	(500.0)
Cash flows from financing activities
Net proceeds from equity offerings	0.0	973.0
Borrowings under credit facilities	600.0	1,820.0
Repayments of credit facilities	0.0	(1,573.0)
Contributions from general partner	0.0	20.0
Capital distributions to general partner	(510.0)	(739.0)
Distributions to noncontrolling interests	(13.0)	(11.0)
Distributions to unitholders and general partner	(379.0)	(302.0)
Other contributions from Parent	9.0	7.0
Credit facility issuance costs	0.0	(1.0)
Repayment of finance leases	(1.0)	0.0
Net cash (used in) provided by financing activities	(294.0)	194.0
Net increase in cash and cash equivalents	86.0	62.0
Cash and cash equivalents at beginning of the period	208.0	138.0
Cash and cash equivalents at end of the period	294.0	200.0
Non-cash investing and financing transactions:
Change in accrued capital expenditures	(2.0)	1.0
Other non-cash contributions from Parent	$ 0.0	$ 2.0