DERIVATIVE INSTRUMENTS - Fair Value and Notional Amounts of Derivatives With Counterparty Credit Risk (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	$ 32,788	$ 43,927
Asset Derivatives Fair Value	543	1,207
Liability Derivatives Fair Value	(1,121)	(1,998)
AA
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	24,508	6,844
Asset Derivatives Fair Value	385	247
Liability Derivatives Fair Value	(977)	(308)
A
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	7,839	36,019
Asset Derivatives Fair Value	149	900
Liability Derivatives Fair Value	(76)	(1,621)
BBB
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Notional Amount of Derivatives	441	1,064
Asset Derivatives Fair Value	9	60
Liability Derivatives Fair Value	$ (68)	$ (69)