INVESTMENTS - Fair Value and Gross Unrealized Losses for Securities That Have Been in Continuous Unrealized Loss Position (Detail) - Fixed maturity securities - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	$ 27,143	$ 7,914
Total Unrealized Losses	3,554	239
Less than 12 months Fair Value	20,642	2,948
Less than 12 months Unrealized Losses	2,381	42
12 months or Longer Fair Value	6,501	4,966
12 months or Longer Unrealized Losses	1,173	197
Dollar-denominated | U.S. government and agencies
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	51	1
Total Unrealized Losses	8	1
Less than 12 months Fair Value	0	0
Less than 12 months Unrealized Losses	5	1
12 months or Longer Fair Value	51	1
12 months or Longer Unrealized Losses	3	0
Dollar-denominated | Municipalities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	708	82
Total Unrealized Losses	105	2
Less than 12 months Fair Value	675	79
Less than 12 months Unrealized Losses	95	2
12 months or Longer Fair Value	33	3
12 months or Longer Unrealized Losses	10	0
Dollar-denominated | Mortgage- and asset-backed securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	839	278
Total Unrealized Losses	74	2
Less than 12 months Fair Value	723	278
Less than 12 months Unrealized Losses	63	2
12 months or Longer Fair Value	116	0
12 months or Longer Unrealized Losses	11	0
Dollar-denominated | Public utilities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	1,544	130
Total Unrealized Losses	181	5
Less than 12 months Fair Value	1,486	70
Less than 12 months Unrealized Losses	171	2
12 months or Longer Fair Value	58	60
12 months or Longer Unrealized Losses	10	3
Dollar-denominated | Sovereign and supranational
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	29	37
Total Unrealized Losses	13	6
Less than 12 months Fair Value	0	6
Less than 12 months Unrealized Losses	0	1
12 months or Longer Fair Value	29	31
12 months or Longer Unrealized Losses	13	5
Dollar-denominated | Banks/financial institutions
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	968	292
Total Unrealized Losses	97	3
Less than 12 months Fair Value	760	274
Less than 12 months Unrealized Losses	69	3
12 months or Longer Fair Value	208	18
12 months or Longer Unrealized Losses	28	0
Dollar-denominated | Other corporate
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	8,276	1,365
Total Unrealized Losses	1,119	53
Less than 12 months Fair Value	7,463	458
Less than 12 months Unrealized Losses	905	8
12 months or Longer Fair Value	813	907
12 months or Longer Unrealized Losses	214	45
Yen-denominated | Japan government and agencies
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	8,091	2,868
Total Unrealized Losses	1,158	61
Less than 12 months Fair Value	4,300	445
Less than 12 months Unrealized Losses	482	3
12 months or Longer Fair Value	3,791	2,423
12 months or Longer Unrealized Losses	676	58
Yen-denominated | Municipalities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	278	187
Total Unrealized Losses	40	5
Less than 12 months Fair Value	166	53
Less than 12 months Unrealized Losses	18	0
12 months or Longer Fair Value	112	134
12 months or Longer Unrealized Losses	22	5
Yen-denominated | Mortgage- and asset-backed securities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	69	33
Total Unrealized Losses	8	1
Less than 12 months Fair Value	46	0
Less than 12 months Unrealized Losses	4	0
12 months or Longer Fair Value	23	33
12 months or Longer Unrealized Losses	4	1
Yen-denominated | Public utilities
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	1,041	26
Total Unrealized Losses	87	2
Less than 12 months Fair Value	929	0
Less than 12 months Unrealized Losses	79	0
12 months or Longer Fair Value	112	26
12 months or Longer Unrealized Losses	8	2
Yen-denominated | Sovereign and supranational
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	68
Total Unrealized Losses	1
Less than 12 months Fair Value	34
Less than 12 months Unrealized Losses	1
12 months or Longer Fair Value	34
12 months or Longer Unrealized Losses	0
Yen-denominated | Banks/financial institutions
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	3,485	2,074
Total Unrealized Losses	399	72
Less than 12 months Fair Value	2,625	1,011
Less than 12 months Unrealized Losses	281	16
12 months or Longer Fair Value	860	1,063
12 months or Longer Unrealized Losses	118	56
Yen-denominated | Other corporate
Investments, Unrealized Loss Position [Line Items]
Total Fair Value	1,696	541
Total Unrealized Losses	264	26
Less than 12 months Fair Value	1,435	274
Less than 12 months Unrealized Losses	208	4
12 months or Longer Fair Value	261	267
12 months or Longer Unrealized Losses	$ 56	$ 22