DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	$ (447)	$ (934)
Gross amount of assets offset in balance sheet	0	0
Net amount of derivative liabilities presented in balance sheet	(447)	(934)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0	0
Derivative, Collateral, Right to Reclaim Cash	24	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(423)	(934)
Interest rate swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(1)	(3)
Gross amount of assets offset in balance sheet	0	0
Net amount of derivative liabilities presented in balance sheet	(1)	(3)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(1)	(3)
Foreign currency swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(284)	(329)
Gross amount of assets offset in balance sheet	0	0
Net amount of derivative liabilities presented in balance sheet	(284)	(329)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0	0
Derivative, Collateral, Right to Reclaim Cash	10	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(274)	(329)
Foreign currency forwards
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(94)	(535)
Gross amount of assets offset in balance sheet	0	0
Net amount of derivative liabilities presented in balance sheet	(94)	(535)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0	0
Derivative, Collateral, Right to Reclaim Cash	14	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(80)	(535)
Foreign currency options
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(22)
Gross amount of assets offset in balance sheet	0
Net amount of derivative liabilities presented in balance sheet	(22)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0
Derivative, Collateral, Right to Reclaim Cash	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(22)
Credit default swaps
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	(46)	(67)
Gross amount of assets offset in balance sheet	0	0
Net amount of derivative liabilities presented in balance sheet	(46)	(67)
Financial instruments, amount not offset against derivative liabilities in balance sheet	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	(46)	(67)
Offsetting liabilities
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments	(1,953)	(7,211)
Gross amounts offset in balance sheet	0	0
Net amounts of liabilities presented in balance sheet	(1,953)	(7,211)
Carrying value of financial instruments not offset in balance sheet	1,470	6,122
Cash collateral not offset in balance sheet	24	0
Financial instruments, amount offset against collateral	(459)	(1,089)
Offsetting liabilities | Securities lending and similar arrangements
Offsetting Liabilities [Line Items]
Gross amounts of recognized financial instruments	(1,506)	(6,277)
Gross amounts offset in balance sheet	0	0
Net amounts of liabilities presented in balance sheet	(1,506)	(6,277)
Carrying value of financial instruments not offset in balance sheet	1,470	6,122
Cash collateral not offset in balance sheet	0	0
Financial instruments, amount offset against collateral	$ (36)	$ (155)