DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) - USD ($) $ in Millions		Mar. 31, 2016		Dec. 31, 2015
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		$ (332)		$ (371)
Gross amount of assets offset in balance sheet		0		0
Net amount of derivative liabilities presented in balance sheet		(332)		(371)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0		0
Derivative, collateral, right to reclaim cash		74	[1]	3
Derivative Liability, Fair Value, Amount Offset Against Collateral		(258)		(351)
Derivative, collateral, right to reclaim securities and cash	[2]			20
Derivative, collateral, right to reclaim securities				17
Foreign currency swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(272)		(314)
Gross amount of assets offset in balance sheet		0		0
Net amount of derivative liabilities presented in balance sheet		(272)		(314)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0		0
Derivative, collateral, right to reclaim cash		33
Derivative Liability, Fair Value, Amount Offset Against Collateral		(239)		(313)
Derivative, collateral, right to reclaim securities and cash				1
Foreign currency forwards
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(36)		(49)
Gross amount of assets offset in balance sheet		0		0
Net amount of derivative liabilities presented in balance sheet		(36)		(49)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0		0
Derivative, collateral, right to reclaim cash		24
Derivative Liability, Fair Value, Amount Offset Against Collateral		(12)		(31)
Derivative, collateral, right to reclaim securities and cash				18
Foreign currency options
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities		(24)		(8)
Gross amount of assets offset in balance sheet		0		0
Net amount of derivative liabilities presented in balance sheet		(24)		(8)
Financial instruments, amount not offset against derivative liabilities in balance sheet		0		0
Derivative, collateral, right to reclaim cash		17
Derivative Liability, Fair Value, Amount Offset Against Collateral		(7)		(7)
Derivative, collateral, right to reclaim securities and cash				1
Offsetting liabilities
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments		(1,162)		(1,312)
Gross amounts offset in balance sheet		0		0
Net amounts of liabilities presented in balance sheet		(1,162)		(1,312)
Carrying value of financial instruments not offset in balance sheet		790		921
Collateral not offset in balance sheet		74		20
Financial instruments, amount offset against collateral		(298)		(371)
Offsetting liabilities | Securities lending and similar arrangements
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments		(830)		(941)
Gross amounts offset in balance sheet		0		0
Net amounts of liabilities presented in balance sheet		(830)		(941)
Carrying value of financial instruments not offset in balance sheet		790		921
Collateral not offset in balance sheet		0		0
Financial instruments, amount offset against collateral		$ (40)		$ (20)

[1] Consists entirely of cash.

[2] Consists of $17 of pledged securities and $3 of cash