STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net income	$ 4,238.5	$ 2,855.6	$ 2,553.0
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	1,791.6	1,644.0	1,552.0
Asset impairment and related charges	50.5	49.8	53.5
Equity in income of unconsolidated affiliates	(480.0)	(426.0)	(362.0)
Distributions received on earnings from unconsolidated affiliates	479.4	433.7	380.5
Net gains attributable to asset sales	(28.7)	(10.7)	(2.5)
Deferred income tax expense	21.4	6.1	6.6
Change in fair market value of derivative instruments	17.8	22.8	45.0
Change in fair market value of Liquidity Option Agreement	56.1	64.3	24.5
Gain on step acquisition of unconsolidated affiliate	(39.4)	0.0	0.0
Net effect of changes in operating accounts	16.2	32.2	(180.9)
Other operating activities	2.9	(5.5)	(2.9)
Net cash flows provided by operating activities	6,126.3	4,666.3	4,066.8
Investing activities:
Capital expenditures	(4,223.2)	(3,101.8)	(2,984.1)
Cash used for business combinations, net of cash received	(150.6)	(198.7)	(1,000.0)
Investments in unconsolidated affiliates	(113.6)	(50.5)	(138.8)
Distributions received for return of capital from unconsolidated affiliates	50.0	49.3	71.0
Proceeds from asset sales	161.2	40.1	46.5
Other investing activities	(5.4)	(24.5)	(0.4)
Cash used in investing activities	(4,281.6)	(3,286.1)	(4,005.8)
Financing activities:
Borrowings under debt agreements	79,588.7	69,315.3	62,813.9
Repayments of debt	(77,957.1)	(68,459.6)	(61,672.6)
Debt issuance costs	(49.1)	(24.1)	(10.6)
Monetization of interest rate derivative instruments	22.1	30.6	6.1
Cash distributions paid to limited partners	(3,726.9)	(3,569.9)	(3,300.5)
Cash payments made in connection with distribution equivalent rights	(17.7)	(15.1)	(11.7)
Cash distributions paid to noncontrolling interests	(81.6)	(49.2)	(47.4)
Cash contributions from noncontrolling interests	238.1	0.4	20.4
Net cash proceeds from the issuance of common units	538.4	1,073.4	2,542.8
Common units acquired in connection with buyback program	(30.8)	0.0	0.0
Other financing activities	(29.0)	(29.3)	(18.7)
Cash provided by (used in) financing activities	(1,504.9)	(1,727.5)	321.7
Net change in cash and cash equivalents, including restricted cash	339.8	(347.3)	382.7
Cash and cash equivalents, including restricted cash, at beginning of period	70.3	417.6	34.9
Cash and cash equivalents, including restricted cash, at end of period	$ 410.1	$ 70.3	$ 417.6