FAIR VALUE MEASUREMENTS Fair Value Inputs Assets Quantitative Information (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2015	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 66,685	$ 68,270
Asset derivatives		752	802
Assets, fair value		$ 70,713	$ 73,901
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		$ 242	$ 401
Asset derivatives		100	106
Assets, fair value		342	507
Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		64,442	65,573
Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		239	249
Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		2,214	2,669
Perpetual securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		0	149
Equity securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		29	28
Equity securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3	3
Equity securities | Net Asset Value Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3	3
Equity securities | Net Asset Value Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 3	$ 3
Equity securities | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		$ 1	$ 1
Equity securities | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		667	677
Equity securities | Assets | Weighted Average | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Offered Quotes		$ 7	$ 6
Mortgage- and asset-backed securities | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 597	$ 602
Mortgage- and asset-backed securities | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		214	223
Mortgage- and asset-backed securities | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		214	223
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		214	223
Banks/financial institutions | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		6,389	6,598
Banks/financial institutions | Fixed Maturities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		25	26
Banks/financial institutions | Fixed Maturities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		25	84
Banks/financial institutions | Fixed Maturities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		25	26
Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		2,011	2,438
Banks/financial institutions | Perpetual securities | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		0	149
Banks/financial institutions | Perpetual securities | Consensus Pricing Valuation Technique
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			149
Banks/financial institutions | Perpetual securities | Consensus Pricing Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities			149
Foreign currency swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		609	746
Foreign currency swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		99	106
Credit default swaps
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		1
Credit default swaps | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		1
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 3	$ 8
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.29%	20.50%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		0.29%	0.16%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		1.57%	1.05%
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 96	$ 98
Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Foreign Exchange Rates	[1]	20.29%	20.50%
Fair Value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Credit default swaps | Assets | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Entity Credit Risk		0.97%
Fair Value Inputs, Recovery Rate		36.69%
Fair Value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Credit default swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	[2]	55.00%
Fair Value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Credit default swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Base Correlation	[2]	58.00%
Fair Value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Credit default swaps | Fixed Maturities | Discounted Cash Flow Valuation Technique | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset derivatives		$ 1
Dollar-denominated | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		37,150	$ 36,285
Dollar-denominated | Mortgage- and asset-backed securities | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		239	216
Dollar-denominated | Banks/financial institutions | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		3,649	3,710
Dollar-denominated | Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 163	$ 175
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.46%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.94%	2.70%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.46%	2.28%
Dollar-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[3]	2.94%	2.70%
Yen-denominated | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 27,292	$ 29,288
Yen-denominated | Mortgage- and asset-backed securities | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		358	386
Yen-denominated | Banks/financial institutions | Fixed Maturities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		2,740	2,888
Yen-denominated | Banks/financial institutions | Perpetual securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Available-for-sale Securities		$ 1,848	$ 2,263
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	0.63%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), CDS Spreads and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	1.48%	1.34%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Lower Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	0.63%	0.53%
Yen-denominated | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and Foreign Exchange Rates | Foreign currency swaps | Assets | Upper Limit | Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	[4]	1.48%	1.34%

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

[2] Range of base correlation for our bespoke tranche for attachment and detachment points corresponding to market indices

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

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