Equity - Common Stock (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jul. 02, 2012	Dec. 31, 2011
Common Stock [Details]
Common shares, authorized	500,000,000		500,000,000			500,000,000
Common shares, outstanding	296,000,000		296,000,000			295,000,000
Total issuances - shares	100,000	400,000	900,000	1,400,000
Issuance through IPP - shares			0	0
Total issuances - net proceeds	$ 3	$ 18	$ 6	$ 26
Issuances through IPP - net proceeds			$ 0	$ 1
Merger Share Exchange Ratio, Adjusted					0.87083
Common Stock Shares, Merger					100
PEC
Common Stock [Details]
Common shares, authorized	200,000,000		200,000,000			200,000,000
Common shares, outstanding	160,000,000		160,000,000			160,000,000
PEF
Common Stock [Details]
Common shares, authorized	60,000,000		60,000,000			60,000,000
Common shares, outstanding	100		100			100