POLICY LIABILITIES - Reconciliation of Future Policy Benefits (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Liability for Future Policy Benefit, Activity [Line Items]
Deferred profit liability - limited-payment contracts	$ 1,788	$ 1,740
Deferred profit liability - reinsurance	682	692
Future policy benefits	91,293	88,241
Corporate and other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	31	19
Cancer | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	36,345	35,468
Medical and other health | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	11,472	10,705
Life insurance | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	25,311	24,469
Life insurance | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	844	802
Accident | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	586	564
Disability | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	812	810
Critical Care | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	7,224	7,003
Hospital Indemnity | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	878	854
Dental/Vision | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	281	277
Other | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	4,514	4,326
Other | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	$ 525	$ 512