STATEMENTS OF CONSOLIDATED CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities:
Net income	$ 2,428.0	$ 2,088.3	$ 1,383.7
Reconciliation of net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	1,104.9	1,007.0	985.1
Non-cash asset impairment charges (see Note 6)	63.4	27.8	8.4
Equity in income of unconsolidated affiliates	(64.3)	(46.4)	(62.0)
Distributions received from unconsolidated affiliates	116.7	156.4	191.9
Gains attributable to disposal of assets (see Note 20)	(86.4)	(155.7)	(46.7)
Deferred income tax expense (benefit)	(66.2)	12.1	7.9
Changes in fair market value of derivative instruments	(29.5)	(25.7)	21.6
Net effect of changes in operating accounts (see Note 20)	(582.5)	266.9	(190.4)
Other operating activities	6.8	(0.2)	0.5
Net cash flows provided by operating activities	2,890.9	3,330.5	2,300.0
Investing activities:
Capital expenditures	(3,621.9)	(3,867.5)	(2,040.8)
Contributions in aid of construction costs	23.4	24.9	38.7
Decrease (increase) in restricted cash	34.2	60.2	(35.0)
Cash used for business combinations (see Note 10)	0	0	(1,313.9)
Investments in unconsolidated affiliates	(609.5)	(30.0)	(8.0)
Proceeds from disposal of assets (see Note 20)	1,198.8	1,053.8	105.9
Other investing activities	(43.8)	(19.0)	1.5
Cash used in investing activities	(3,018.8)	(2,777.6)	(3,251.6)
Financing activities:
Borrowings under debt agreements	8,363.1	8,324.1	6,484.4
Repayments of debt	(6,676.4)	(7,375.8)	(5,344.4)
Debt issuance costs	(21.5)	(34.7)	(22.5)
Monetization of interest rate derivative instruments (see Note 6)	(147.8)	(23.2)	1.3
Cash distributions paid to limited partners (see Note 13)	(2,178.6)	(1,974.3)	(307.7)
Cash distributions paid to noncontrolling interests (see Note 13)	(13.3)	(60.7)	(1,467.8)
Cash contributions from noncontrolling interests (see Note 13)	6.6	8.5	1,096.5
Net cash proceeds from issuance of common units	816.8	542.9	528.5
Other financing activities	(24.7)	(5.4)	(7.2)
Cash provided by (used in) financing activities	124.2	(598.6)	961.1
Effect of exchange rate changes on cash	0	0	0.7
Net change in cash and cash equivalents	(3.7)	(45.7)	9.5
Cash and cash equivalents, January 1	19.8	65.5	55.3
Cash and cash equivalents, December 31	$ 16.1	$ 19.8	$ 65.5