FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Assets:
Available-for-sale Securities	$ 67,403	$ 68,270
Asset derivatives	877	802
Other Investments	182	171
Cash and cash equivalents	3,520	4,658
Total assets	71,982	73,901
Liabilities:
Liability derivatives	384	2,423
Total liabilities	384	2,423
Foreign currency swaps
Assets:
Asset derivatives	604	746
Liabilities:
Liability derivatives	352	318
Foreign currency forwards
Assets:
Asset derivatives	268	56
Liabilities:
Liability derivatives	24	1,912
Foreign currency options
Assets:
Asset derivatives	5
Liabilities:
Liability derivatives	8	33
Interest rate swaptions
Liabilities:
Liability derivatives		160
Fixed Maturities
Assets:
Available-for-sale Securities	65,106	65,573
Fixed Maturities | Government and agencies debt securities
Assets:
Available-for-sale Securities	18,465	19,198
Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	1,166	1,257
Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	591	602
Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	7,848	7,897
Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,421	1,416
Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	6,261	6,598
Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	29,354	28,605
Perpetual securities
Assets:
Available-for-sale Securities	2,166	2,669
Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	1,964	2,438
Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	202	231
Equity securities
Assets:
Available-for-sale Securities	131	28
Level 1
Assets:
Available-for-sale Securities	18,042	18,702
Asset derivatives	0	0
Other Investments	182	171
Cash and cash equivalents	3,520	4,658
Total assets	21,744	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
Assets:
Asset derivatives	0
Liabilities:
Liability derivatives	0	0
Level 1 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 1 | Fixed Maturities
Assets:
Available-for-sale Securities	17,920	18,683
Level 1 | Fixed Maturities | Government and agencies debt securities
Assets:
Available-for-sale Securities	17,920	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	122	19
Level 2
Assets:
Available-for-sale Securities	49,112	49,167
Asset derivatives	771	696
Other Investments	0	0
Cash and cash equivalents	0	0
Total assets	49,883	49,863
Liabilities:
Total liabilities	41	2,105
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	498	640
Liabilities:
Liability derivatives	9	0
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	268	56
Liabilities:
Liability derivatives	24	1,912
Level 2 | Foreign currency options
Assets:
Asset derivatives	5
Liabilities:
Liability derivatives	8	33
Level 2 | Interest rate swaptions
Liabilities:
Liability derivatives		160
Level 2 | Fixed Maturities
Assets:
Available-for-sale Securities	46,940	46,641
Level 2 | Fixed Maturities | Government and agencies debt securities
Assets:
Available-for-sale Securities	545	515
Level 2 | Fixed Maturities | Municipalities
Assets:
Available-for-sale Securities	1,166	1,257
Level 2 | Fixed Maturities | Mortgage- and asset-backed securities
Assets:
Available-for-sale Securities	371	379
Level 2 | Fixed Maturities | Public utilities
Assets:
Available-for-sale Securities	7,848	7,897
Level 2 | Fixed Maturities | Sovereign and supranational
Assets:
Available-for-sale Securities	1,421	1,416
Level 2 | Fixed Maturities | Banks/financial institutions
Assets:
Available-for-sale Securities	6,235	6,572
Level 2 | Fixed Maturities | Other corporate
Assets:
Available-for-sale Securities	29,354	28,605
Level 2 | Perpetual securities
Assets:
Available-for-sale Securities	2,166	2,520
Level 2 | Perpetual securities | Banks/financial institutions
Assets:
Available-for-sale Securities	1,964	2,289
Level 2 | Perpetual securities | Other corporate
Assets:
Available-for-sale Securities	202	231
Level 2 | Equity securities
Assets:
Available-for-sale Securities	6	6
Level 3
Assets:
Available-for-sale Securities	249	401
Asset derivatives	106	106
Other Investments	0	0
Cash and cash equivalents	0	0
Total assets	355	507
Liabilities:
Total liabilities	343	318
Level 3 | Foreign currency swaps
Assets:
Asset derivatives	106	106
Liabilities:
Liability derivatives	343	318
Level 3 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 3 | Foreign currency options
Assets:
Asset derivatives	0
Liabilities:
Liability derivatives	0	0
Level 3 | Interest rate swaptions
Liabilities:
Liability derivatives		0
Level 3 | Fixed Maturities
Assets:
Available-for-sale Securities	246	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	220	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	26	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	106	106
Total assets	4,996	4,785
Liabilities:
Liability derivatives	343	318
Total liabilities	$ 343	$ 318