CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (Variable Interest Entity [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Variable Interest Entity [Member]
Current Assets:
Cash and cash equivalents, VIE	$ 220	$ 198
Accounts and notes receivable, net, VIE	52	49
Other, VIE	42	39
Other Assets:
Regulatory assets, VIE	$ 2,289	$ 2,597