CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
OPERATING ACTIVITIES
Net income	$ 255	$ 114
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,362	1,479
Deferred income taxes	133	68
Provision for uncollectible accounts	33	53
Long-term debt premium amortization	(34)	(47)
Net loss on early retirement of debt		37
Changes in current assets and current liabilities:
Accounts receivable	(56)	(73)
Accounts payable	12	(76)
Accounts receivable and payable-affiliates, net		(307)
Accrued income and other taxes	(6)	(8)
Other current assets and other current liabilities, net	(86)	(27)
Retirement benefits	(51)	(96)
Changes in other noncurrent assets and liabilities, net	(16)	(43)
Other, net		4
Net cash provided by operating activities	1,546	1,078
INVESTING ACTIVITIES
Payments for property, plant and equipment and capitalized software	(801)	(752)
Changes in advances to affiliates	(1,323)	669
Proceeds from sale of property		133
Net cash (used in) provided by investing activities	(2,124)	50
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	752	897
Payments of long-term debt	(811)	(2,251)
Early retirement of debt costs		(177)
Changes in notes payable-affiliates	631	583
Changes in advances from affiliates	(20)	(187)
Net cash provided by (used in) financing activities	552	(1,135)
Net decrease in cash and cash equivalents	(26)	(7)
Cash and cash equivalents at beginning of period	87	48
Cash and cash equivalents at end of period	61	41
Supplemental cash flow information:
Income taxes (paid), net	(4)	(1)
Interest (paid) (net of capitalized interest of $12 and $12)	$ (353)	$ (453)