PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Actual Returns (Losses) on Assets Held by Our Pension Trusts (Details) (Pension, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Actual return (loss) on plan assets	$ 49	$ 515	$ 691
Direct investments
Defined Benefit Plan Disclosure [Line Items]
Actual return (loss) on plan assets	48	362	525
Derivatives
Defined Benefit Plan Disclosure [Line Items]
Actual return (loss) on plan assets	$ 1	$ 153	$ 166