FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Available-for-Sale Securities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	$ 67,318	$ 61,038
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,421	14,942
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	48,551	45,649
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	346	447
Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	64,281	58,070
Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,407	14,928
Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	45,587	42,750
Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	287	392
Perpetual securities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3,016	2,947
Perpetual securities: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Perpetual securities: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	2,960	2,895
Perpetual securities: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	56	52
Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	21	21
Equity Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	14	14
Equity Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	4	4
Equity Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Equity Securities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18	18
Equity Securities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	14	14
Equity Securities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	4	4
Equity Securities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity Securities | Net Asset Value Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Equity Securities | Net Asset Value Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity Securities | Net Asset Value Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Equity Securities | Net Asset Value Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	3	3
Government and Agencies Debt Securities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,906	15,432
Government and Agencies Debt Securities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,407	14,928
Government and Agencies Debt Securities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	499	504
Government and Agencies Debt Securities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,906	15,432
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	18,407	14,928
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	499	504
Government and Agencies Debt Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,097	1,051
Municipalities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,097	1,051
Municipalities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,097	1,051
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,097	1,051
Municipalities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed Securities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	666	771
Mortgage- and asset-backed Securities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	404	402
Mortgage- and asset-backed Securities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	262	369
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	404	402
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	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 Basis [Line Items]
Available-for-sale Securities	404	402
Mortgage- and asset-backed Securities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	262	369
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	262	369
Public Utilities | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,926	7,562
Public Utilities | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public Utilities | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,926	7,562
Public Utilities | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,926	7,562
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	7,926	7,562
Public Utilities | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and Supranational | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,544	1,523
Sovereign and Supranational | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and Supranational | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,544	1,523
Sovereign and Supranational | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,544	1,523
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	1,544	1,523
Sovereign and Supranational | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6,792	6,509
Banks/financial Institutions | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6,767	6,486
Banks/financial Institutions | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	25	23
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6,767	6,486
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	6,767	6,486
Banks/financial Institutions | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	25	23
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	25	23
Banks/financial Institutions | Perpetual securities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	2,787	2,738
Banks/financial Institutions | Perpetual securities: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Perpetual securities: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	2,731	2,686
Banks/financial Institutions | Perpetual securities: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	56	52
Banks/financial Institutions | Perpetual securities: | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	2,787	2,738
Banks/financial Institutions | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Banks/financial Institutions | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	2,731	2,686
Banks/financial Institutions | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	56	52
Banks/financial Institutions | Perpetual securities: | Consensus Pricing Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		52
Other Corporate | Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	27,350	25,222
Other Corporate | Fixed Maturities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Fixed Maturities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	27,350	25,222
Other Corporate | Fixed Maturities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	27,350	25,220
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	27,350	25,220
Other Corporate | Fixed Maturities | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		2
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		0
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		2
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities		0
Other Corporate | Perpetual securities:
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	229	209
Other Corporate | Perpetual securities: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Perpetual securities: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	229	209
Other Corporate | Perpetual securities: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Perpetual securities: | Third party pricing vendor valuation technique [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	229	209
Other Corporate | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	0	0
Other Corporate | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	229	209
Other Corporate | Perpetual securities: | Third party pricing vendor valuation technique [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale Securities	$ 0	$ 0