CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash Flows from Operating Activities:
Net Income	$ 128	$ 118
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	77	69
Amortization of deferred financing costs	3	3
Deferred income taxes	76	70
Write-down of natural gas inventory	0	4
Equity in earnings of unconsolidated affiliates, net of distributions	4	2
Changes in other assets and liabilities:
Accounts receivable and unbilled revenues, net.	(71)	189
Accounts receivable/payable, affiliates	10	2
Inventory	122	97
Taxes receivable	0	(1)
Accounts payable	(36)	(153)
Fuel cost recovery	105	(43)
Interest and taxes accrued	23	16
Non-trading derivatives, net	6	(1)
Margin deposits, net	12	14
Other current assets	4	(4)
Other current liabilities	(40)	(33)
Other assets	(4)	3
Other liabilities	34	9
Other, net	0	1
Net cash provided by operating activities	453	362
Cash Flows from Investing Activities:
Capital expenditures, net of acquisitions	(116)	(114)
Investment in unconsolidated affiliates	0	(4)
Other, net	(2)	0
Net cash used in investing activities	(118)	(118)
Cash Flows from Financing Activities:
Decrease in short-term borrowings, net	(38)	(53)
Proceeds from (payments of) commercial paper, net	61	(285)
Increase (decrease) in notes payable to affiliates	(339)	94
Other, net	0	4
Net cash used in financing activities	(316)	(240)
Net Increase in Cash and Cash Equivalents	19	4
Cash and Cash Equivalents at Beginning of Period	1	1
Cash and Cash Equivalents at End of Period	20	5
Cash Payments:
Interest, net of capitalized interest	32	33
Non-cash transactions:
Accounts payable related to capital expenditures	$ 40	$ 39