DERIVATIVE INSTRUMENTS - Offsetting of Financial Assets and Derivative Assets (Details) - USD ($) $ in Millions		Jun. 30, 2015		Dec. 31, 2014
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets		$ 752		$ 802
Gross amount of liabilities offset in balance sheet		0		0
Net amount of derivative assets presented in balance sheet		752		802
Financial instruments, amount not offset against derivative assets in balance sheet		0		0
Derivative, Collateral, Obligation to Return Cash		(624)	[1]	(466)
Derivative, Collateral, Obligation to Return Cash and Securities	[2]			(619)
Derivative asset, fair value, amount offset against collateral		128		183
Derivative, Collateral, Obligation to Return Securities				(153)
Foreign currency swaps
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets		609		746
Gross amount of liabilities offset in balance sheet		0		0
Net amount of derivative assets presented in balance sheet		609		746
Financial instruments, amount not offset against derivative assets in balance sheet		0		0
Derivative, Collateral, Obligation to Return Cash		(520)
Derivative, Collateral, Obligation to Return Cash and Securities				(568)
Derivative asset, fair value, amount offset against collateral		89		178
Foreign currency forwards
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets		142		56
Gross amount of liabilities offset in balance sheet		0		0
Net amount of derivative assets presented in balance sheet		142		56
Financial instruments, amount not offset against derivative assets in balance sheet		0		0
Derivative, Collateral, Obligation to Return Cash		(104)
Derivative, Collateral, Obligation to Return Cash and Securities				(51)
Derivative asset, fair value, amount offset against collateral		38		5
Credit default swaps
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets		1
Gross amount of liabilities offset in balance sheet		0
Net amount of derivative assets presented in balance sheet		1
Financial instruments, amount not offset against derivative assets in balance sheet		0
Derivative, Collateral, Obligation to Return Cash		0
Derivative asset, fair value, amount offset against collateral		1
Offsetting assets
Offsetting Assets [Line Items]
Gross amounts of recognized financial instruments		1,755		2,951
Gross amounts offset in balance sheet		0		0
Net amounts of assets presented in balance sheet		1,755		2,951
Carrying value of financial instruments not offset in balance sheet		0		0
Collateral not offset in balance sheet		(1,627)		(2,768)
Financial instruments, amount offset against collateral		128		183
Offsetting assets | Securities lending and similar arrangements
Offsetting Assets [Line Items]
Gross amounts of recognized financial instruments		1,003		2,149
Gross amounts offset in balance sheet		0		0
Net amounts of assets presented in balance sheet		1,003		2,149
Carrying value of financial instruments not offset in balance sheet		0		0
Collateral not offset in balance sheet		(1,003)		(2,149)
Financial instruments, amount offset against collateral		$ 0		$ 0

[1] Consists entirely of cash.

[2] Consists of $153 of pledged securities and $466 of cash.