UNAUDITED CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net income	$ 670.2	$ 650.6
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	382.1	367.4
Non-cash asset impairment charges	1.7	33.3
Equity in income of unconsolidated affiliates	(101.1)	(89.2)
Distributions received on earnings from unconsolidated affiliates	106.7	134.4
Net losses (gains) attributable to asset sales	4.9	(0.1)
Deferred income tax expense	4.1	1.5
Changes in fair market value of derivative instruments	20.1	(4.6)
Net effect of changes in operating accounts	(186.4)	(139.0)
Other operating activities	(2.6)	(0.3)
Net cash flows provided by operating activities	899.7	954.0
Investing activities:
Capital expenditures	(1,007.2)	(812.8)
Contributions in aid of construction costs	12.2	19.6
Increase in restricted cash	(121.0)	(28.2)
Investments in unconsolidated affiliates	(70.4)	(68.3)
Distributions received for return of capital from unconsolidated affiliates	9.1	0.0
Proceeds from asset sales	13.4	0.5
Other investing activities	0.0	0.1
Cash used in investing activities	(1,163.9)	(889.1)
Financing activities:
Borrowings under debt agreements	20,000.6	9,182.5
Repayments of debt	(19,797.4)	(8,953.2)
Debt issuance costs	0.0	(0.1)
Cash distributions paid to limited partners	(788.3)	(703.8)
Cash payments made in connection with distribution equivalent rights	(2.0)	(1.2)
Cash distributions paid to noncontrolling interests	(8.7)	(16.5)
Cash contributions from noncontrolling interests	11.1	4.0
Net cash proceeds from the issuance of common units	1,011.5	468.4
Other financing activities	(21.0)	(38.3)
Cash provided by (used in) financing activities	405.8	(58.2)
Net change in cash and cash equivalents	141.6	6.7
Cash and cash equivalents, beginning balance	19.0	74.4
Cash and cash equivalents, ending balance	$ 160.6	$ 81.1