INCOME TAXES - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2012	Sep. 30, 2012
Schedule Of Income Tax [Line Items]
Income tax impact	$ 721	$ 641	$ 521			$ 1,900
Maximum of decrease in the tax relief attributable to decommissioning expenditures				50.00%
Non-recurring tax charge						$ 118
Company's administrative appeals tax years					2004 through 2008
Calendar period for audit, year one					2009
Calendar period for audit					2010