FAIR VALUE MEASUREMENTS - Changes in Available-For-Sale Investments and Derivatives Classified as Level 3 (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		$ 366	$ 341	$ 223	$ 58
Realized investment gains (losses) included in earnings		7	(16)	35	252
Unrealized gains (losses) included in other comprehensive income (loss)		(1)	1	7	32
Purchases		53	0	177	0
Issuances		0	0	0	0
Sales		(1)	0	(2)	0
Settlements		(8)	(13)	(24)	(29)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Balance, end of period		416	313	416	313
Change in unrealized gains (losses) still held		7	(16)	35	252
Foreign currency swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	[1]	7	59	(21)	(192)
Realized gains or losses included in earnings	[1]	8	(18)	36	250
Unrealized gains or losses included in other comprehensive income (loss)	[1]	0	0	0	(16)
Purchases	[1]	0	0	0	0
Issuances	[1]	0	0	0	0
Sales	[1]	0	0	0	0
Settlements	[1]	0	0	0	(1)
Transfers into Level 3	[1]	0	0	0	0
Transfers out of Level 3	[1]	0	0	0	0
Balance, end of period	[1]	15	41	15	41
Changes in unrealized gain (losses) still held	[1]	8	(18)	36	250
Credit default swaps
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	[1]	2	1	2	1
Realized gains or losses included in earnings	[1]	(1)	2	(1)	2
Unrealized gains or losses included in other comprehensive income (loss)	[1]	0	0	0	0
Purchases	[1]	0	0	0	0
Issuances	[1]	0	0	0	0
Sales	[1]	0	0	0	0
Settlements	[1]	0	0	0	0
Transfers into Level 3	[1]	0	0	0	0
Transfers out of Level 3	[1]	0	0	0	0
Balance, end of period	[1]	1	3	1	3
Changes in unrealized gain (losses) still held	[1]	(1)	2	(1)	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		188	252	198	220
Realized investment gains (losses) included in earnings		0	0	0	0
Unrealized gains (losses) included in other comprehensive income (loss)		(2)	1	4	48
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		0	0	0	0
Settlements		(8)	(13)	(24)	(28)
Transfers into Level 3		0	0	0	0
Transfers out of Level 3		0	0	0	0
Balance, end of period		178	240	178	240
Change in unrealized gains (losses) still held		0	0	0	0
Fixed maturities | Public utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		53	0	16	0
Realized investment gains (losses) included in earnings		0	0	0	0
Unrealized gains (losses) included in other comprehensive income (loss)		0	0	0	0
Purchases		24	0	61	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		77	0	77	0
Change in unrealized gains (losses) still held		0	0	0	0
Fixed maturities | Banks/financial institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		25	26	25	26
Realized investment gains (losses) included in earnings		0	0	0	0
Unrealized gains (losses) included in other comprehensive income (loss)		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		25	26	25	26
Change in unrealized gains (losses) still held		0	0	0	0
Fixed maturities | Other corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		77	0	0	0
Realized investment gains (losses) included in earnings		0	0	0	0
Unrealized gains (losses) included in other comprehensive income (loss)		1	0	3	0
Purchases		25	0	100	0
Issuances		0	0	0	0
Sales		(1)	0	(1)	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		102	0	102	0
Change in unrealized gains (losses) still held		0	0	0	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period		14	3	3	3
Realized investment gains (losses) included in earnings		0	0	0	0
Unrealized gains (losses) included in other comprehensive income (loss)		0	0	0	0
Purchases		4	0	16	0
Issuances		0	0	0	0
Sales		0	0	(1)	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		18	3	18	3
Change in unrealized gains (losses) still held		$ 0	$ 0	$ 0	$ 0

[1] Derivative assets and liabilities are presented net