INCOME TAXES - Items Excluded from Effective Income Tax Rates (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2012 Income taxes on postretirement plan amendment discussed in Note 6	Mar. 31, 2012 Income taxes on postretirement plan amendment discussed in Note 6	Mar. 31, 2012 State income tax settlements	Sep. 30, 2012 Income tax settlements	Jun. 30, 2012 Income tax settlements
Income tax credit (charge) that is excluded from the company's effective income tax rate	$ 0	$ (18)	$ (18)	$ 8	$ 7	$ (3)