PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Fair Value of Derivatives (Details) (Qualified and Registered Pension Plans, USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	$ 223	$ 328
Equity index instruments
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	1	17
Forward contracts
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	2	(4)
Swaps
Defined Benefit Plan Disclosure [Line Items]
Derivatives, Fair Value, Net	$ 220	$ 315