DERIVATIVE INSTRUMENTS - Fair Value and Notional Amounts of Derivatives With Counterparty Credit Risk (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	$ 23,106	$ 22,127
Asset Derivatives Fair Value	1,963	676
Liability Derivatives Fair Value	(542)	(371)
AA
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	2,875	2,187
Asset Derivatives Fair Value	173	166
Liability Derivatives Fair Value	(126)	(35)
A
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	19,131	19,940
Asset Derivatives Fair Value	1,691	510
Liability Derivatives Fair Value	(352)	(336)
BBB
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	1,100	0
Asset Derivatives Fair Value	99	0
Liability Derivatives Fair Value	$ (64)	$ 0