Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2014

Balance Sheet Components [Abstract]

Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]

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

	Three Months Ended March 31,
	2014			2013
Balance as of beginning of period	$	6		$	5
Provision, net	2			2
Amounts written off, less recoveries	(1		)	(1		)
Balance as of end of period	$	7		$	6

Schedule of Other Current Assets [Table Text Block]

Other current assets consist of the following (in millions):

	March 31, 2014		December 31, 2013
Prepaid expenses	$	53	$	38
Current deferred income tax asset	43		42
Assets from price risk management activities	18		13
Other	—		1
Other current assets	$	114	$	94

Schedule of Public Utility Property, Plant, and Equipment [Table Text Block]

Electric utility plant, net consists of the following (in millions):

	March 31, 2014			December 31, 2013
Electric utility plant	$	7,144		$	7,095
Construction work-in-progress	633			508
Total cost	7,777			7,603
Less: accumulated depreciation and amortization	(2,768		)	(2,723		)
Electric utility plant, net	$	5,009		$	4,880

Schedule of Regulatory Assets and Liabilities [Text Block]

Regulatory assets and liabilities consist of the following (in millions):

	March 31, 2014					December 31, 2013
	Current			Noncurrent		Current			Noncurrent
Regulatory assets:
Price risk management	$	34		$	123	$	36		$	140
Pension and other postretirement plans	—			189		—			194
Deferred income taxes	—			78		—			76
Deferred broker settlements	8			—		12			1
Debt reacquisition costs	—			16		—			17
Deferred capital projects	11			19		16			18
Other	2			23		2			18
Total regulatory assets	$	55		$	448	$	66		$	464
Regulatory liabilities:
Asset retirement removal costs	$	—		$	762	$	—		$	747
Trojan decommissioning activities	—			42		—			41
Asset retirement obligations	—			39		—			39
Other	2			56		1			38
Total regulatory liabilities	$	2	*	$	899	$	1	*	$	865

* Included in Accrued expenses and other current liabilities in the condensed consolidated balance sheets.

Other Liabilities Disclosure [Text Block]

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

	March 31, 2014		December 31, 2013
Accrued employee compensation and benefits	$	38	$	46
Accrued interest payable	36		23
Accrued taxes payable	28		21
Accrued dividends payable	22		22
Regulatory liabilities—current	2		1
Other	56		58
Total accrued expenses and other current liabilities	$	182	$	171

Pension and Other Postretirement Benefits Disclosure [Text Block]

Components of net periodic benefit cost are as follows (in millions):

	Three Months Ended March 31,
	Defined Benefit Pension Plan						Other Postretirement Benefits
	2014			2013			2014		2013
Service cost	$	4		$	4		$	—	$	1
Interest cost	9			8			1		1
Expected return on plan assets	(10		)	(10		)	—		—
Amortization of net actuarial loss	4			6			—		—
Net periodic benefit cost	$	7		$	8		$	1	$	2