Decommissioning Trust Funds (Tables)

3 Months Ended

Mar. 31, 2012

Decommissioning Trust Fund [Abstract]

Securities Held

	Fair Value	Total Unrealized Gains	Total Unrealized Losses
	(In Millions)
2012
Equity Securities	$2,370	$633	$1
Debt Securities	1,669	101	6
Total	$4,039	$734	$7
2011
Equity Securities	$2,129	$423	$14
Debt Securities	1,659	115	5
Total	$3,788	$538	$19

Available For Sale Securities Continuous Unrealized Loss Position Fair Value

The fair value and gross unrealized losses of available-for-sale equity and debt securities, summarized by investment type and length of time that the securities have been in a continuous loss position, are as follows as of March 31, 2012:

	Equity Securities		Debt Securities
	Fair Value	Gross Unrealized Losses	Fair Value	Gross Unrealized Losses
	(In Millions)
Less than 12 months	$12	$-	$284	$3
More than 12 months	24	1	56	3
Total	$36	$1	$340	$6

The fair value and gross unrealized losses of available-for-sale equity and debt securities, summarized by investment type and length of time that the securities have been in a continuous loss position, are as follows as of December 31, 2011:

	Equity Securities		Debt Securities
	Fair Value	Gross Unrealized Losses	Fair Value	Gross Unrealized Losses
	(In Millions)
Less than 12 months	$130	$9	$123	$3
More than 12 months	43	5	60	2
Total	$173	$14	$183	$5

Fair Value Of Debt Securities By Contractual Maturities

	2012	2011
	(In Millions)
Less than 1 year	$54	$69
1 year - 5 years	618	566
5 years - 10 years	568	583
10 years - 15 years	197	187
15 years - 20 years	42	42
20 years+	190	212
Total	$1,669	$1,659