FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Assets:
Available-for-sale Securities	$ 66,685	$ 68,270
Asset derivatives	752	802
Other Investments	199	171
Other Investments	173
Cash and cash equivalents	3,103	4,658
Total assets	70,713	73,901
Liabilities:
Liability derivatives	502	2,423
Total liabilities	502	2,423
Foreign currency swaps
Assets:
Asset derivatives	609	746
Liabilities:
Liability derivatives	326	318
Foreign currency forwards
Assets:
Asset derivatives	142	56
Liabilities:
Liability derivatives	176	1,912
Foreign currency options
Liabilities:
Liability derivatives		33
Credit default swaps
Assets:
Asset derivatives	1
Interest rate swaptions
Liabilities:
Liability derivatives		160
Fixed Maturities
Assets:
Available-for-sale Securities	64,442	65,573
Fixed Maturities | Government and Agencies Debt Securities
Assets:
Available-for-sale Securities	17,717	19,198
Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	1,155	1,257
Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	597	602
Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	7,776	7,897
Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,437	1,416
Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	6,389	6,598
Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	29,371	28,605
Perpetual securities
Assets:
Available-for-sale Securities	2,214	2,669
Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	2,011	2,438
Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	203	231
Equity securities
Assets:
Available-for-sale Securities	29	28
Level 1
Assets:
Available-for-sale Securities	17,197	18,702
Asset derivatives	0	0
Other Investments		171
Other Investments	173
Cash and cash equivalents	3,103	4,658
Total assets	20,473	23,531
Liabilities:
Total liabilities	0	0
Level 1 | Foreign currency swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Foreign currency options
Liabilities:
Liability derivatives		0
Level 1 | Credit default swaps
Assets:
Asset derivatives	0
Level 1 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 1 | Fixed Maturities
Assets:
Available-for-sale Securities	17,177	18,683
Level 1 | Fixed Maturities | Government and Agencies Debt Securities
Assets:
Available-for-sale Securities	17,177	18,683
Level 1 | Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	0
Level 1 | Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	0
Level 1 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 1 | Equity securities
Assets:
Available-for-sale Securities	20	19
Level 2
Assets:
Available-for-sale Securities	49,246	49,167
Asset derivatives	652	696
Other Investments		0
Other Investments	0
Cash and cash equivalents	0	0
Total assets	49,898	49,863
Liabilities:
Total liabilities	180	2,105
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	510	640
Liabilities:
Liability derivatives	4	0
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	142	56
Liabilities:
Liability derivatives	176	1,912
Level 2 | Foreign currency options
Liabilities:
Liability derivatives		33
Level 2 | Credit default swaps
Assets:
Asset derivatives	0
Level 2 | Interest rate swaptions
Liabilities:
Liability derivatives		160
Level 2 | Fixed Maturities
Assets:
Available-for-sale Securities	47,026	46,641
Level 2 | Fixed Maturities | Government and Agencies Debt Securities
Assets:
Available-for-sale Securities	540	515
Level 2 | Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	1,155	1,257
Level 2 | Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	383	379
Level 2 | Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	7,776	7,897
Level 2 | Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,437	1,416
Level 2 | Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	6,364	6,572
Level 2 | Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	29,371	28,605
Level 2 | Perpetual securities
Assets:
Available-for-sale Securities	2,214	2,520
Level 2 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	2,011	2,289
Level 2 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	203	231
Level 2 | Equity securities
Assets:
Available-for-sale Securities	6	6
Level 3
Assets:
Available-for-sale Securities	242	401
Asset derivatives	100	106
Other Investments		0
Other Investments	0
Cash and cash equivalents	0	0
Total assets	342	507
Liabilities:
Total liabilities	322	318
Level 3 | Foreign currency swaps
Assets:
Asset derivatives	99	106
Liabilities:
Liability derivatives	322	318
Level 3 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 3 | Foreign currency options
Liabilities:
Liability derivatives		0
Level 3 | Credit default swaps
Assets:
Asset derivatives	1
Level 3 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 3 | Fixed Maturities
Assets:
Available-for-sale Securities	239	249
Level 3 | Fixed Maturities | Government and Agencies Debt Securities
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	214	223
Level 3 | Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	0	0
Level 3 | Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	25	26
Level 3 | Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 3 | Perpetual securities
Assets:
Available-for-sale Securities	0	149
Level 3 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	0	149
Level 3 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	0	0
Level 3 | Equity securities
Assets:
Available-for-sale Securities	3	3
Variable Interest Entity, Consolidated
Assets:
Asset derivatives	100	106
Total assets	4,892	4,785
Liabilities:
Liability derivatives	322	318
Total liabilities	$ 322	$ 318