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, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			$ 9,132	$ 9,239	$ 9,239
Capitalization			508		1,086
Amortization expense	$ (208)	$ (202)	(424)	(407)	(816)
Foreign currency translation and other			(666)		(377)
Balance, end of period	8,550		8,550		9,132
Aflac Japan | Cancer
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			2,971	3,035	3,035
Capitalization			146		317
Amortization expense			(92)		(184)
Foreign currency translation and other			(358)		(197)
Balance, end of period	2,667		2,667		2,971
Aflac Japan | Medical and other health
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			2,041	2,161	2,161
Capitalization			55		123
Amortization expense			(50)		(105)
Foreign currency translation and other			(244)		(138)
Balance, end of period	1,802		1,802		2,041
Aflac Japan | Life insurance
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			491	525	525
Capitalization			15		33
Amortization expense			(16)		(34)
Foreign currency translation and other			(58)		(33)
Balance, end of period	432		432		491
Aflac Japan | Other
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			56	55	55
Capitalization			2		8
Amortization expense			(2)		(3)
Foreign currency translation and other			(6)		(4)
Balance, end of period	50		50		56
Aflac U.S. | Life insurance
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			172	135	135
Capitalization			31		61
Amortization expense			(14)		(24)
Foreign currency translation and other			0		0
Balance, end of period	189		189		172
Aflac U.S. | Accident
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			917	904	904
Capitalization			68		151
Amortization expense			(72)		(138)
Foreign currency translation and other			0		0
Balance, end of period	913		913		917
Aflac U.S. | Disability
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			625	613	613
Capitalization			62		125
Amortization expense			(59)		(113)
Foreign currency translation and other			0		0
Balance, end of period	628		628		625
Aflac U.S. | Critical Care
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			1,336	1,304	1,304
Capitalization			81		173
Amortization expense			(77)		(141)
Foreign currency translation and other			0		0
Balance, end of period	1,340		1,340		1,336
Aflac U.S. | Hospital Indemnity
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			436	418	418
Capitalization			41		84
Amortization expense			(36)		(66)
Foreign currency translation and other			0		0
Balance, end of period	441		441		436
Aflac U.S. | Dental/Vision
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			86	88	88
Capitalization			6		10
Amortization expense			(6)		(12)
Foreign currency translation and other			0		0
Balance, end of period	86		86		86
Aflac U.S. | Other
Deferred Policy Acquisition Cost [Line Items]
Balance, beginning of period			1	$ 1	1
Capitalization			1		1
Amortization expense			0		4
Foreign currency translation and other			0		(5)
Balance, end of period	$ 2		$ 2		$ 1