COMMON EQUITY (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Dec. 31, 2011	Dec. 31, 2010	May 31, 2010
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 127	[1]	$ 135	[1]
Stockholders' Equity Note [Abstract]
Common Shareholders' Equity	3,977				3,889
Common Stock, Shares, Outstanding	130.4				127.4
Forward Contract Indexed to Issuer's Equity, Indexed Shares							6.6
Dividends declared	(65)		(62)
Losses recognized on cash flow hedges, net of tax	(10)		(5)
Common Stock, Shares Authorized	200				200
Common stock issued	26		25
Common Stockholders' Equity			$ 3,800			$ 3,702

[1] (1) Accumulated other comprehensive loss totaled $88.1 million as of March 31, 2012 and $93.8 million as of December 31, 2011.