STATEMENTS OF CONSOLIDATED CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows from Operating Activities:
Net Income	$ 137	$ 316	$ 300
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	285	262	248
Amortization of deferred financing costs	13	13	9
Deferred income taxes	245	144	208
Goodwill impairment	252	0	0
Step acquisition gain	(136)	0	0
Write-down of natural gas inventory	4	11	6
Equity in earnings of unconsolidated affiliates, net of distributions	8	8	13
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net.	6	67	120
Accounts receivable/payable, affiliates	5	(14)	6
Inventory	41	20	(52)
Taxes receivable	1	62	(16)
Accounts payable	2	(101)	(35)
Fuel cost recovery	(52)	(70)	(9)
Interest and taxes accrued	(11)	6	5
Non-trading derivatives, net	19	(10)	(5)
Margin deposits, net.	53	34	7
Other current assets	(10)	11	(20)
Other current liabilities	8	(12)	(14)
Other assets	(13)	(3)	(7)
Other liabilities	(28)	22	(21)
Other, net	7	3	(21)
Net cash provided by operating activities	836	769	722
Cash Flows from Investing Activities:
Capital expenditures, net of acquisitions	(566)	(644)	(917)
Acquisitions, net of cash acquired	(360)	0	0
Investment in unconsolidated affiliates	(5)	(12)	(18)
Other, net	8	10	20
Net cash used in investing activities	(923)	(646)	(915)
Cash Flows from Financing Activities:
Increase (decrease) in short-term borrowings, net	(24)	9	(2)
Proceeds from (payments of) commercial paper, net	(285)	102	183
Proceeds from long-term debt	0	550	0
Payments of long-term debt	0	(606)	(45)
Cash paid for debt exchange	0	(58)	0
Debt issuance costs	0	(14)	0
Increase (decrease) in notes payable to affiliates	396	(106)	57
Net cash provided by (used in) financing activities	87	(123)	193
Net Decrease in Cash and Cash Equivalents	0	0	0
Cash and Cash Equivalents at Beginning of the Year	1	1	1
Cash and Cash Equivalents at End of the Year	1	1	1
Cash Payments:
Interest, net of capitalized interest	163	177	191
Income taxes (refunds), net	3	(20)	141
Non-cash transactions:
Accounts payable related to capital expenditures	$ 60	$ 53	$ 98