POLICY LIABILITIES - Schedule of Changes in Other Policyholders' Funds (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Mar. 31, 2023	Dec. 31, 2022
Policyholder Account Balance [Line Items]
Total		$ 6,668	$ 6,643
Aflac Japan
Policyholder Account Balance [Line Items]
Other deposit type reserves		292	220
Total		6,668	6,643
Aflac Japan | Fixed Annuity
Policyholder Account Balance [Line Items]
Beginning balance	[1]	6,423	7,410
Premiums received	[1]	39	150
Transfers from WAYS conversions	[1]	58	214
Surrenders and withdrawals	[1]	(14)	(52)
Benefit payments	[1]	(104)	(367)
Interest credited	[1]	14	57
Foreign currency translation and other	[1]	(40)	(989)
Ending balance	[1]	$ 6,376	$ 6,423

[1] Aflac Japan fixed annuities