DERIVATIVE INSTRUMENTS - Fair Value and Notional Amounts of Derivatives With Counterparty Credit Risk (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	$ 28,250	$ 43,927
Asset Derivatives Fair Value	479	1,207
Liability Derivatives Fair Value	(974)	(1,998)
AA
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	5,553	6,844
Asset Derivatives Fair Value	90	247
Liability Derivatives Fair Value	(189)	(308)
A
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	22,257	36,019
Asset Derivatives Fair Value	381	900
Liability Derivatives Fair Value	(718)	(1,621)
BBB
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	440	1,064
Asset Derivatives Fair Value	8	60
Liability Derivatives Fair Value	$ (67)	$ (69)