FAIR VALUE MEASUREMENTS Fair Value Inputs Assets Quantitative Information (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2013		Dec. 31, 2012
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	$ 58,666		$ 61,578
Asset derivatives	620		345
Assets, fair value	61,674		63,964
Length of Volatility of Japanese Yen to US Dollar Exchange Rate	10 years		10 years
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	476		3,405
Asset derivatives	135		191
Assets, fair value	611		3,596
Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	55,810		57,253
Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	424		3,186
Perpetual Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	2,834		4,302
Perpetual Securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	49		215
Equity Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	22		23
Equity Securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	3		4
Equity Securities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	3		4
Equity Securities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	3		4
Equity Securities | Net Asset Value Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	3		4
Equity Securities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			6
Equity Securities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			0
Equity Securities | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes	$ 1		$ 2
Equity Securities | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes	$ 828		$ 943
Equity Securities | Assets | Weighted Average | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes	$ 7		$ 8
Public Utilities | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Volatility Rate			7.36%
Public Utilities | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	7,866		8,497
Public Utilities | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		420
Public Utilities | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	24		25
Public Utilities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		0
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			3,328
Public Utilities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			420
Sovereign and Supranational | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Volatility Rate			7.36%
Sovereign and Supranational | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	1,661		2,072
Sovereign and Supranational | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		418
Sovereign and Supranational | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	298		495
Sovereign and Supranational | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		0
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			1,037
Sovereign and Supranational | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			418
Mortgage- and asset-backed Securities | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	895		1,031
Mortgage- and asset-backed Securities | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	399		338
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	399		338
Mortgage- and asset-backed Securities | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	399		338
Mortgage- and asset-backed Securities | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			11
Mortgage- and asset-backed Securities | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			0
Banks/financial Institutions | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Volatility Rate			7.36%
Banks/financial Institutions | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	6,694		7,634
Banks/financial Institutions | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	25		1,024
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	30		797
Banks/financial Institutions | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	25		580
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			2,580
Banks/financial Institutions | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			444
Banks/financial Institutions | Perpetual Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	2,631		3,950
Banks/financial Institutions | Perpetual Securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	49		215
Banks/financial Institutions | Perpetual Securities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	49
Banks/financial Institutions | Perpetual Securities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			3,667
Banks/financial Institutions | Perpetual Securities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			215
Banks/financial Institutions | Perpetual Securities | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Volatility Rate			7.36%
Other Corporate | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Volatility Rate			7.36%
Other Corporate | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	25,201		23,827
Other Corporate | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		986
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	2		412
Other Corporate | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		411
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			5,322
Other Corporate | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			575
Other Corporate | Perpetual Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	203		352
Other Corporate | Perpetual Securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities	0		0
Other Corporate | Perpetual Securities | Discounted Cash Flow Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			352
Other Corporate | Perpetual Securities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			0
Interest rate swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	22		32
Interest rate swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	22		32
Interest rate swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	22		32
Interest rate swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	52.00%	[1]	49.00%	[1]
Fair Value Inputs, Entity Credit Risk	0.92%		0.91%
Interest rate swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	63.00%	[1]	50.00%	[1]
Fair Value Inputs, Entity Credit Risk	1.51%		1.52%
Interest rate swaps | Assets | Weighted Average | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	57.00%	[1]
Fair Value Inputs, Entity Credit Risk	1.23%
Fair Value Inputs, Recovery Rate	37.00%		37.00%
Foreign currency swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	381		311
Foreign currency swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	111		157
Credit default swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	2		2
Credit default swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	2		2
Credit default swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	2		2
Credit default swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	52.00%		49.00%
Fair Value Inputs, Entity Credit Risk	0.92%		0.91%
Credit default swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	63.00%		50.00%
Fair Value Inputs, Entity Credit Risk	1.51%		1.52%
Credit default swaps | Assets | Weighted Average | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	57.00%
Fair Value Inputs, Entity Credit Risk	1.23%
Fair Value Inputs, Recovery Rate	37.00%		37.00%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	32		51
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	21.39%	[2]	20.65%	[2]
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk	0.35%		0.12%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk	1.50%		1.17%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	5		4
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk	0.13%		0.12%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk	1.30%		1.26%
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives	$ 74		$ 102
Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	21.39%	[2]	20.65%	[2]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	1.02%	[3]	0.84%	[3]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.03%	[3]	2.05%	[3]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	1.02%	[3]	0.84%	[3]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.03%	[3]	2.05%	[3]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	1.02%	[3]	0.84%	[3]
Japan, Yen | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.03%	[3]	2.05%	[3]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.70%	[4]	1.84%	[4]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	3.47%	[4]	2.84%	[4]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.70%	[4]	1.84%	[4]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	3.47%	[4]	2.84%	[4]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	2.70%	[4]	1.84%	[4]
United States of America, Dollars | Fair Value, Unobservable Input, Interest Rates (USD), interest rates (JPY), and Foreign Exchange Rates [Member] | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	3.47%	[4]	2.84%	[4]

[1] Weighted-average range of base correlations for our bespoke tranches for attachment and detachment points corresponding to market indices

[2] Based on 10 year volatility of JPY/USD exchange rate

[3] Inputs derived from Japan long-term rates to accommodate long maturity nature of our swaps

[4] Inputs derived from U.S. long-term rates to accommodate long maturity nature of our swaps