SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES -Schedule of Impact from Adoption to AOCI and Retained Earnings (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Total transition impact		$ (19,784)	$ (20,140)	$ (17,560)	$ (17,031)		$ (33,559)
Accumulated other comprehensive income (loss)
Total transition impact		7,278	6,429	8,451	8,411		(8,934)
Retained earnings
Total transition impact		$ (45,555)	$ (44,367)	$ (42,010)	$ (40,963)		$ (37,984)
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12
Total transition impact						$ 18,894
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss)
Impact to AOCI						23,507
Less: income taxes						4,937
Total transition impact						18,570
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Corporate and other
Impact to AOCI						218
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Cancer | Aflac Japan
Impact to AOCI						14,529
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Medical and other health | Aflac Japan
Impact to AOCI						2,382
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Life insurance | Aflac Japan
Impact to AOCI						3,314
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Life insurance | Aflac U.S.
Impact to AOCI						149
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Accident | Aflac U.S.
Impact to AOCI						92
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Disability | Aflac U.S.
Impact to AOCI						149
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Critical Care | Aflac U.S.
Impact to AOCI						2,258
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Hospital Indemnity | Aflac U.S.
Impact to AOCI						223
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Dental/Vision | Aflac U.S.
Impact to AOCI						65
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Other | Reinsurance ceded
Impact to AOCI						(305)
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Accumulated other comprehensive income (loss) | Other | Aflac U.S.
Impact to AOCI						433
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings
Impact to retained earnings						410
Less: income taxes						86
Total transition impact						324
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Corporate and other
Impact to retained earnings						2
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Cancer | Aflac Japan
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Medical and other health | Aflac Japan
Impact to retained earnings						1
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Life insurance | Aflac Japan
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Life insurance | Aflac U.S.
Impact to retained earnings						5
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Accident | Aflac U.S.
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Disability | Aflac U.S.
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Critical Care | Aflac U.S.
Impact to retained earnings						4
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Hospital Indemnity | Aflac U.S.
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Dental/Vision | Aflac U.S.
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Other | Reinsurance ceded
Impact to retained earnings						0
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2018-12 | Retained earnings | Other | Aflac U.S.
Impact to retained earnings	[1]					$ 398

[1] Impact to retained earnings is driven primarily by capping the Transition Date NPR on Care products.