DEFERRED POLICY ACQUISITION COSTS - Schedule Of Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			$ 9,239	$ 9,848	$ 9,848
Capitalization			525		1,052
Amortization expense	$ (202)	$ (197)	(407)	(405)	(792)
Foreign currency translation and other			(497)		(869)
Ending balance	8,860		8,860		9,239
Aflac Japan | Cancer
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			3,035	3,464	3,464
Capitalization			153		291
Amortization expense			(94)		(188)
Foreign currency translation and other			(262)		(532)
Ending balance	2,832		2,832		3,035
Aflac Japan | Medical and other health
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			2,161	2,372	2,372
Capitalization			63		161
Amortization expense			(54)		(112)
Foreign currency translation and other			(185)		(260)
Ending balance	1,985		1,985		2,161
Aflac Japan | Life insurance
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			525	595	595
Capitalization			18		33
Amortization expense			(18)		(35)
Foreign currency translation and other			(44)		(68)
Ending balance	481		481		525
Aflac Japan | Other
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			55	51	51
Capitalization			5		12
Amortization expense			(2)		(3)
Foreign currency translation and other			(4)		(5)
Ending balance	54		54		55
Aflac U.S. | Life insurance
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			135	115	115
Capitalization			27		40
Amortization expense			(11)		(20)
Foreign currency translation and other			0		0
Ending balance	151		151		135
Aflac U.S. | Accident
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			904	887	887
Capitalization			76		147
Amortization expense			(69)		(130)
Foreign currency translation and other			0		0
Ending balance	911		911		904
Aflac U.S. | Disability
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			613	604	604
Capitalization			59		117
Amortization expense			(56)		(108)
Foreign currency translation and other			0		0
Ending balance	616		616		613
Aflac U.S. | Critical Care
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			1,304	1,270	1,270
Capitalization			80		160
Amortization expense			(67)		(126)
Foreign currency translation and other			0		0
Ending balance	1,317		1,317		1,304
Aflac U.S. | Hospital Indemnity
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			418	399	399
Capitalization			39		80
Amortization expense			(32)		(61)
Foreign currency translation and other			0		0
Ending balance	425		425		418
Aflac U.S. | Dental/Vision
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			88	90	90
Capitalization			5		11
Amortization expense			(6)		(13)
Foreign currency translation and other			0		0
Ending balance	87		87		88
Aflac U.S. | Other
Deferred Policy Acquisition Cost [Line Items]
Beginning balance			1	$ 1	1
Capitalization			0		0
Amortization expense			2		4
Foreign currency translation and other			(2)		(4)
Ending balance	$ 1		$ 1		$ 1