DERIVATIVE INSTRUMENTS - Fair Value and Notional Amounts of Derivatives With Counterparty Credit Risk (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Fair Value of Swaps	$ (110)	$ (156)
Notional Amount of Swaps	6,028	5,491
AA
Derivative [Line Items]
Fair Value of Swaps	14	0
Notional Amount of Swaps	272	0
A
Derivative [Line Items]
Fair Value of Swaps	(124)	(156)
Notional Amount of Swaps	$ 5,756	$ 5,491