FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Held-to-Maturity Securities (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	$ 42,761	$ 54,841
Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	42,761	54,841
Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24,682	32,332
Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	18,033	22,445
Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	46	64
Government and Agencies Debt Securities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24,682	32,332
Government and Agencies Debt Securities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24,682	32,332
Government and Agencies Debt Securities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and Agencies Debt Securities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24,682	32,332
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24,682	32,332
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	467	520
Municipalities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	467	520
Municipalities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	467	464
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	467	464
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Municipalities | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		56
Municipalities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Municipalities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		56
Municipalities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Mortgage- and asset-backed Securities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	70	94
Mortgage- and asset-backed Securities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24	30
Mortgage- and asset-backed Securities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	46	64
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24	30
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	24	30
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	46	64
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	46	64
Public Utilities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,192	5,051
Public Utilities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public Utilities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,192	5,051
Public Utilities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,192	58
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	4,192	58
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		4,993
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		4,993
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Sovereign and Supranational | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,844	3,317
Sovereign and Supranational | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and Supranational | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,844	3,317
Sovereign and Supranational | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,844	370
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	2,844	370
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		2,947
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		2,947
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Banks/financial Institutions | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	6,632	8,991
Banks/financial Institutions | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial Institutions | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	6,632	8,991
Banks/financial Institutions | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	6,632	254
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	6,632	254
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		8,737
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		8,737
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Other Corporate | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,874	4,536
Other Corporate | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other Corporate | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,874	4,536
Other Corporate | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,874	122
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	3,874	122
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value	0	0
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		4,414
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		0
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		4,414
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity, fixed maturities, fair value		$ 0