SONGS NDT 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 641								$ 627
Gross Unrealized Gains	459								417
Gross Unrealized Loss	(4)								(10)
Estimated Fair Value	1,096								1,034
Proceeds from sales	155	[1]	192	[1]	350	[1]	326	[1]
Gross realized gains	0		6		4		11
Gross realized losses	1		4		5		7
Total Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	400								381
Gross Unrealized Gains	19								8
Gross Unrealized Loss	(3)								(8)
Estimated Fair Value	416								381
Debt Securities Issued By The U.S. Treasury And Other U.S. Government Corporations And Agencies
Schedule of Available-for-sale Securities [Line Items]
Cost	101	[2]							116
Gross Unrealized Gains	5	[2]							3
Gross Unrealized Loss	0	[2]							(2)
Estimated Fair Value	106	[2]							117
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Cost	109	[3]							110
Gross Unrealized Gains	6	[3]							2
Gross Unrealized Loss	(1)	[3]							(1)
Estimated Fair Value	114	[3]							111
Other Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	190	[4]							155
Gross Unrealized Gains	8	[4]							3
Gross Unrealized Loss	(2)	[4]							(5)
Estimated Fair Value	196	[4]							153
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	213								207
Gross Unrealized Gains	440								409
Gross Unrealized Loss	(1)								(2)
Estimated Fair Value	652								614
Cash And Cash Equivalents
Schedule of Available-for-sale Securities [Line Items]
Cost	28								39
Gross Unrealized Gains	0								0
Gross Unrealized Loss	0								0
Estimated Fair Value	$ 28								$ 39

[1] (1) Excludes securities that are held to maturity.

[2] Maturity dates are 2016-2060

[3] Maturity dates are 2014-2062

[4] Maturity dates are 2014-2096