Condensed Statements Of Consolidated Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows - operating activities:
Net income	$ 196	$ 197
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	459	440
Provision in lieu of deferred income taxes - net	(46)	(4)
Other - net	(1)	(2)
Changes in operating assets and liabilities:
Deferred revenues (Note 4)	(16)	(29)
Changes in other operating assets and liabilities	(18)	(211)
Cash provided by operating activities	574	391
Cash flows - financing activities:
Issuances of long-term debt (Note 6)	725	250
Repayments of long-term debt (Note 6)	(569)	(65)
Net increase in short-term borrowings (Note 5)	69	77
Distributions to members (Note 8)	(165)	(110)
Debt discount, premium, financing and reacquisition expenses - net	(12)	(4)
Cash provided by financing activities	48	148
Cash flows - investing activities:
Capital expenditures	(625)	(572)
Other - net	15	11
Cash used in investing activities	(610)	(561)
Net change in cash and cash equivalents	12	(22)
Cash and cash equivalents - beginning balance	4	27
Cash and cash equivalents - ending balance	$ 16	$ 5