FAIR VALUE MEASUREMENTS - Changes in Available-For-Sale Investments and Derivatives Classified as Level 3 (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 3,507		$ 465		$ 3,803		$ 560
Realized gains or losses included in earnings	(45)		(19)		50		(83)
Unrealized gains or losses included in other comprehensive income	48		3		(25)		(25)
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		(290)		0
Settlements	(14)		125		(42)		122
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	3,496		574		3,496		574
Change in unrealized gains (losses) still held	(45)	[1]	17	[2]	(1)	[1]	(60)	[2]
Fixed Maturities | Mortgage- and asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	367		248		394		267
Realized gains or losses included in earnings	(3)		0		(3)		(6)
Unrealized gains or losses included in other comprehensive income	22		12		(1)		2
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	(7)		(3)		(11)		(6)
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	379		257		379		257
Change in unrealized gains (losses) still held	(3)	[1]	0	[2]	(3)	[1]	(6)	[2]
Fixed Maturities | Public Utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	409		0		422		0
Realized gains or losses included in earnings	0		0		0		0
Unrealized gains or losses included in other comprehensive income	9		0		(4)		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	418		0		418		0
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	0	[2]
Fixed Maturities | Collateralized Debt Obligations
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period			5				5
Realized gains or losses included in earnings			(1)				(1)
Unrealized gains or losses included in other comprehensive income			0				0
Purchases			0				0
Issuances			0				0
Sales			0				0
Settlements			0				0
Transfers into Level 3			0				0
Transfers out of Level 3			0				0
Balance, end of period			4				4
Change in unrealized gains (losses) still held			(1)	[2]			(1)	[2]
Fixed Maturities | Sovereign and Supranational
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	418		0		434		0
Realized gains or losses included in earnings	0		0		0		0
Unrealized gains or losses included in other comprehensive income	18		0		2		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	436		0		436		0
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	0	[2]
Fixed Maturities | Banks/financial Institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,097		420		1,074		386
Realized gains or losses included in earnings	0		0		0		1
Unrealized gains or losses included in other comprehensive income	17		(22)		40		11
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	1,114		398		1,114		398
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	1	[2]
Fixed Maturities | Other Corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,035		0		1,105		0
Realized gains or losses included in earnings	0		0		2		0
Unrealized gains or losses included in other comprehensive income	(4)		0		(42)		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		(34)		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	1,031		0		1,031		0
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	0	[2]
Perpetual Securities | Banks/financial Institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	325		0		526		0
Realized gains or losses included in earnings	0		0		49		0
Unrealized gains or losses included in other comprehensive income	(18)		0		(12)		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		(256)		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	307		0		307		0
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	0	[2]
Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	4		4		4		4
Realized gains or losses included in earnings	0		0		0		0
Unrealized gains or losses included in other comprehensive income	0		0		0		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	0		0		0		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	4		4		4		4
Change in unrealized gains (losses) still held	0	[1]	0	[2]	0	[1]	0	[2]
Derivatives | Interest rate swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	28				30
Realized gains or losses included in earnings	(1)				(3)
Unrealized gains or losses included in other comprehensive income	0				0
Purchases	0				0
Issuances	0				0
Sales	0				0
Settlements	0				0
Transfers into Level 3	0				0
Transfers out of Level 3	0				0
Balance, end of period	27				27
Change in unrealized gains (losses) still held	(1)	[1]			(3)	[1]
Derivatives | Foreign currency swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	(79)		126		(56)		241
Realized gains or losses included in earnings	(31)		25		(18)		(39)
Unrealized gains or losses included in other comprehensive income	4		13		(8)		(38)
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	(7)		0		(31)		0
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	(113)		164		(113)		164
Change in unrealized gains (losses) still held	(31)	[1]	25	[2]	(18)	[1]	(39)	[2]
Derivatives | Credit default swaps
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	(97)		(338)		(130)		(343)
Realized gains or losses included in earnings	(10)		(43)		23		(38)
Unrealized gains or losses included in other comprehensive income	0		0		0		0
Purchases	0		0		0		0
Issuances	0		0		0		0
Sales	0		0		0		0
Settlements	0		128		0		128
Transfers into Level 3	0		0		0		0
Transfers out of Level 3	0		0		0		0
Balance, end of period	(107)		(253)		(107)		(253)
Change in unrealized gains (losses) still held	$ (10)	[1]	$ (7)	[2]	$ 23	[1]	$ (15)	[2]

[1] Represents the amount of total gains or losses for the period, included in earnings, attributable to the change in unrealized gains (losses) relating to assets classified as Level 3 that were still held at June 30, 2012

[2] Represents the amount of total gains or losses for the period, included in earnings, attributable to the change in unrealized gains (losses) relating to assets classified as Level 3 that were still held at June 30, 2011