CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Balance Sheet Parenthetical (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Cash and Cash Equivalents	$ 344	$ 646
Accounts and notes receivable, net	301	222
Other	62	77
Regulatory assets	3,206	3,388
Variable Interest Entity, Primary Beneficiary [Member]
Cash and Cash Equivalents	208	266
Accounts and notes receivable, net	89	68
Other	53	54
Regulatory assets	$ 3,364	$ 3,545