DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	$ (2,423)		$ (837)
Gross amount of assets offset in balance sheet	0		0
Net amount of derivative liabilities presented in balance sheet	(2,423)		(837)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0		0
Derivative, Collateral, Right to Reclaim Securities	1,621	[1]	7
Derivative, Collateral, Right to Reclaim Cash			1
Derivative, Collateral, Right to Reclaim Securities and Cash			8	[2]
Derivative Liability, Fair Value, Amount Offset Against Collateral	(802)		(829)
Foreign currency swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(318)		(218)
Gross amount of assets offset in balance sheet	0		0
Net amount of derivative liabilities presented in balance sheet	(318)		(218)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0		0
Derivative, Collateral, Right to Reclaim Securities	0
Derivative, Collateral, Right to Reclaim Securities and Cash			1
Derivative Liability, Fair Value, Amount Offset Against Collateral	(318)		(217)
Foreign currency forwards
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(1,912)		(582)
Gross amount of assets offset in balance sheet	0		0
Net amount of derivative liabilities presented in balance sheet	(1,912)		(582)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0		0
Derivative, Collateral, Right to Reclaim Securities	1,439
Derivative, Collateral, Right to Reclaim Securities and Cash			0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(473)		(582)
Foreign currency options
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(33)		(1)
Gross amount of assets offset in balance sheet	0		0
Net amount of derivative liabilities presented in balance sheet	(33)		(1)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0		0
Derivative, Collateral, Right to Reclaim Securities	24
Derivative, Collateral, Right to Reclaim Securities and Cash			0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(9)		(1)
Credit default swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities			(4)
Gross amount of assets offset in balance sheet			0
Net amount of derivative liabilities presented in balance sheet			(4)
Financial instruments, amount not offset against derivative liabilities in balance sheet			0
Derivative, Collateral, Right to Reclaim Securities and Cash			0
Derivative Liability, Fair Value, Amount Offset Against Collateral			(4)
Interest rate swaptions
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(160)		(32)
Gross amount of assets offset in balance sheet	0		0
Net amount of derivative liabilities presented in balance sheet	(160)		(32)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0		0
Derivative, Collateral, Right to Reclaim Securities	158
Derivative, Collateral, Right to Reclaim Securities and Cash			7
Derivative Liability, Fair Value, Amount Offset Against Collateral	(2)		(25)
Offsetting liabilities
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments	(4,616)		(6,657)
Gross amounts offset in balance sheet	0		0
Net amounts of financial instruments presented in balance sheet	(4,616)		(6,657)
Carrying value of financial instruments not offset in balance sheet	2,149		5,656
Collateral not offset in balance sheet	1,621		8
Financial instruments, amount offset against collateral	(846)		(993)
Offsetting liabilities | Securities lending and similar arrangements
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments	(2,193)		(5,820)
Gross amounts offset in balance sheet	0		0
Net amounts of financial instruments presented in balance sheet	(2,193)		(5,820)
Carrying value of financial instruments not offset in balance sheet	2,149		5,656
Collateral not offset in balance sheet	0		0
Financial instruments, amount offset against collateral	$ (44)		$ (164)

[1] Consists entirely of pledged securities.

[2] Consists of $7 of pledged securities and $1 of cash.