STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities:
Net income	$ 2,855.6	$ 2,553.0	$ 2,558.4
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	1,644.0	1,552.0	1,516.0
Asset impairment and related charges	49.8	53.5	162.6
Equity in income of unconsolidated affiliates	(426.0)	(362.0)	(373.6)
Distributions received on earnings from unconsolidated affiliates	433.7	380.5	462.1
Net losses (gains) attributable to asset sales	(10.7)	(2.5)	15.6
Deferred income tax expense (benefit)	6.1	6.6	(20.6)
Change in fair market value of derivative instruments	22.8	45.0	(18.4)
Change in fair market value of Liquidity Option Agreement	64.3	24.5	25.4
Net effect of changes in operating accounts	32.2	(180.9)	(323.3)
Other operating activities	(5.5)	(2.9)	(1.8)
Net cash flows provided by operating activities	4,666.3	4,066.8	4,002.4
Investing activities:
Capital expenditures	(3,147.9)	(3,025.1)	(3,830.7)
Contributions in aid of construction costs	46.1	41.0	19.1
Cash used for business combinations, net of cash received	(198.7)	(1,000.0)	(1,056.5)
Investments in unconsolidated affiliates	(50.5)	(138.8)	(162.6)
Distributions received for return of capital from unconsolidated affiliates	49.3	71.0	0.0
Proceeds from asset sales	40.1	46.5	1,608.6
Other investing activities	(24.5)	(0.4)	(3.8)
Cash used in investing activities	(3,286.1)	(4,005.8)	(3,425.9)
Financing activities:
Borrowings under debt agreements	69,315.3	62,813.9	21,081.1
Repayments of debt	(68,459.6)	(61,672.6)	(19,867.2)
Debt issuance costs	(24.1)	(10.6)	(24.0)
Monetization of interest rate derivative instruments	30.6	6.1	0.0
Cash distributions paid to limited partners	(3,569.9)	(3,300.5)	(2,943.7)
Cash payments made in connection with distribution equivalent rights	(15.1)	(11.7)	(7.7)
Cash distributions paid to noncontrolling interests	(49.2)	(47.4)	(48.0)
Cash contributions from noncontrolling interests	0.4	20.4	54.0
Net cash proceeds from the issuance of common units	1,073.4	2,542.8	1,188.6
Other financing activities	(29.3)	(18.7)	(49.1)
Cash provided by (used in) financing activities	(1,727.5)	321.7	(616.0)
Net change in cash and cash equivalents	(347.3)	382.7	(39.5)
Cash, cash equivalents and restricted cash, January 1	417.6	34.9	74.4
Cash, cash equivalents and restricted cash, December 31	$ 70.3	$ 417.6	$ 34.9