POLICY LIABILITIES - Schedule of Changes in Other Policyholders' Funds (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2024	Dec. 31, 2023
Policyholder Account Balance [Line Items]
Other deposit type reserves		$ 281	$ 230
Total		6,095	6,169
Aflac Japan | Fixed Annuity
Policyholder Account Balance [Line Items]
Beginning balance	[1]	5,939	6,423
Premiums received	[1]	86	126
Transfers from WAYS conversions	[1]	207	229
Surrenders and withdrawals	[1]	(49)	(59)
Benefit payments	[1]	(373)	(419)
Interest credited	[1]	42	53
Foreign currency translation and other	[1]	(38)	(414)
Ending balance	[1]	$ 5,814	$ 5,939

[1] Aflac Japan fixed annuities