UNAUDITED CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 911.5	$ 771.0
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	431.0	402.3
Asset impairment and related charges	0.9	11.2
Equity in income of unconsolidated affiliates	(115.7)	(94.8)
Distributions received on earnings from unconsolidated affiliates	107.5	90.5
Net gains attributable to asset sales	(0.5)	(0.3)
Deferred income tax expense (benefit)	(1.1)	0.1
Change in fair market value of derivative instruments	136.9	(20.3)
Change in fair market value of Liquidity Option Agreement	7.5	5.5
Gain on step acquisition of unconsolidated affiliate	(37.0)	0.0
Net effect of changes in operating accounts	(203.1)	(288.8)
Other operating activities	(4.3)	(0.8)
Net cash flows provided by operating activities	1,233.6	875.6
Investing activities:
Capital expenditures	(946.5)	(430.4)
Cash used for business combinations, net of cash received	(149.8)	(16.0)
Investments in unconsolidated affiliates	(37.9)	(13.7)
Distributions received for return of capital from unconsolidated affiliates	14.9	12.0
Proceeds from asset sales	1.1	2.0
Other investing activities	(0.9)	2.1
Cash used in investing activities	(1,119.1)	(444.0)
Financing activities:
Borrowings under debt agreements	16,283.8	17,575.1
Repayments of debt	(15,444.7)	(17,856.5)
Debt issuance costs	(24.2)	0.0
Monetization of interest rate derivative instruments	1.5	0.0
Cash distributions paid to limited partners	(918.5)	(869.0)
Cash payments made in connection with distribution equivalent rights	(3.9)	(3.2)
Cash distributions paid to noncontrolling interests	(15.4)	(10.1)
Cash contributions from noncontrolling interests	0.1	0.2
Net cash proceeds from the issuance of common units	177.0	448.8
Other financing activities	(24.9)	(27.4)
Cash provided by (used in) financing activities	30.8	(742.1)
Net change in cash and cash equivalents, including restricted cash	145.3	(310.5)
Cash and cash equivalents, including restricted cash, at beginning of period	70.3	417.6
Cash and cash equivalents, including restricted cash, at end of period	$ 215.6	$ 107.1