STATEMENTS OF CONSOLIDATED CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Net income	$ 2,607.1	$ 2,428.0	$ 2,088.3
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	1,217.6	1,104.9	1,007.0
Non-cash asset impairment charges (see Note 6)	92.6	63.4	27.8
Equity in income of unconsolidated affiliates	(167.3)	(64.3)	(46.4)
Distributions received from unconsolidated affiliates	251.6	116.7	156.4
Gains attributable to asset sales and insurance recoveries (see Note 19)	(83.3)	(86.4)	(155.7)
Deferred income tax expense (benefit)	37.9	(66.2)	12.1
Changes in fair market value of derivative instruments	1.4	(29.5)	(25.7)
Net effect of changes in operating accounts (see Note 19)	(97.6)	(582.5)	266.9
Other operating activities	5.5	6.8	(0.2)
Net cash flows provided by operating activities	3,865.5	2,890.9	3,330.5
Investing activities:
Capital expenditures	(3,408.2)	(3,621.9)	(3,867.5)
Contributions in aid of construction costs	26.0	23.4	24.9
Decrease (increase) in restricted cash	(61.3)	34.2	60.2
Investments in unconsolidated affiliates	(1,094.1)	(609.5)	(30.0)
Proceeds from asset sales and insurance recoveries (see Note 19)	280.6	1,198.8	1,053.8
Other investing activities	(0.5)	(43.8)	(19.0)
Cash used in investing activities	(4,257.5)	(3,018.8)	(2,777.6)
Financing activities:
Borrowings under debt agreements	13,852.8	8,363.1	8,324.1
Repayments of debt	(12,680.6)	(6,676.4)	(7,375.8)
Debt issuance costs	(23.7)	(21.5)	(34.7)
Monetization of interest rate derivative instruments (see Note 6)	(168.8)	(147.8)	(23.2)
Cash distributions paid to limited partners (see Note 12)	(2,400.3)	(2,178.6)	(1,974.3)
Cash distributions paid to noncontrolling interests (see Note 12)	(8.9)	(13.3)	(60.7)
Cash contributions from noncontrolling interests (see Note 12)	115.4	6.6	8.5
Net cash proceeds from the issuance of common units	1,792.0	816.8	542.9
Other financing activities	(45.1)	(24.7)	(5.4)
Cash provided by (used in) financing activities	432.8	124.2	(598.6)
Net change in cash and cash equivalents	40.8	(3.7)	(45.7)
Cash and cash equivalents, January 1	16.1	19.8	65.5
Cash and cash equivalents, December 31	$ 56.9	$ 16.1	$ 19.8