DERIVATIVE INSTRUMENTS - Fair Value and Notional Amount of Derivatives with Counterparty Credit Risk (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value and Notional Amount of Derivatives with Counterparty Credit RIsk [Line Items]
Notional Amount of Derivatives	$ 43,927	$ 22,127
Asset Derivatives Fair Value	1,207	676
Liability Derivatives Fair Value	(1,998)	(371)
AA
Fair Value and Notional Amount of Derivatives with Counterparty Credit RIsk [Line Items]
Notional Amount of Derivatives	6,844	2,187
Asset Derivatives Fair Value	247	166
Liability Derivatives Fair Value	(308)	(35)
A
Fair Value and Notional Amount of Derivatives with Counterparty Credit RIsk [Line Items]
Notional Amount of Derivatives	36,019	19,940
Asset Derivatives Fair Value	900	510
Liability Derivatives Fair Value	(1,621)	(336)
BBB
Fair Value and Notional Amount of Derivatives with Counterparty Credit RIsk [Line Items]
Notional Amount of Derivatives	1,064	0
Asset Derivatives Fair Value	60	0
Liability Derivatives Fair Value	$ (69)	$ 0