Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2012

Balance Sheet Components [Abstract]

Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]

The following is the activity in the allowance for uncollectible accounts (in millions):

	Years Ended December 31,
	2012			2011			2010
Balance as of beginning of year	$	6		$	5		$	5
Increase in provision	6			11			7
Amounts written off, less recoveries	(7		)	(10		)	(7		)
Balance as of end of year	$	5		$	6		$	5

Investments held in trust [Table Text Block]

The trusts are comprised of the following investments as of December 31 (in millions):

	Nuclear     Decommissioning Trust				Non-Qualified Benefit     Plan Trust
	2012		2011		2012		2011
Cash equivalents	$	15	$	14	$	2	$	—
Marketable securities, at fair value:
Equity securities	—		—		5		10
Debt securities	23		23		2		3
Insurance contracts, at cash surrender value	—		—		23		23
	$	38	$	37	$	32	$	36

Schedule of Other Assets and Other Liabilities [Table Text Block]

Other current assets and Accrued expenses and other current liabilities consist of the following (in millions):

	As of December 31,
	2012		2011
Other current assets:
Current deferred income tax asset	$	51	$	33
Assets from price risk management activities	4		19
Income taxes receivable	1		12
Other	37		34
	$	93	$	98
Accrued expenses and other current liabilities:
Accrued employee compensation and benefits	$	46	$	44
Accrued interest payable	23		24
Dividends payable	21		21
Regulatory liabilities—current	12		6
Other	77		62
	$	179	$	157