POLICY LIABILITIES - Reconciliation of Future Policy Benefits (Details) - USD ($) $ in Millions		Sep. 30, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 79,672	$ 83,718
Deferred reinsurance gain liability		165	175
Liability for Future Policy Benefits Reconciling Items
Liability for Future Policy Benefit, Activity [Line Items]
Deferred profit liability		2,000	1,806
Deferred reinsurance gain liability		949	1,012
Intercompany eliminations
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	[1]	(4,711)	(5,017)
Corporate and other | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		3,897	4,225
Cancer | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		30,502	32,652
Cancer | Aflac Japan | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		30,502	32,652
Medical and other health | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		10,103	10,560
Medical and other health | Aflac Japan | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		10,103	10,560
Life insurance | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		21,829	23,243
Life insurance | Aflac Japan | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		21,829	23,243
Life insurance | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		985	911
Life insurance | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		985	911
Accident | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		659	621
Accident | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		659	621
Disability | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		732	770
Disability | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		732	770
Critical Care | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		7,257	7,216
Critical Care | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		7,257	7,216
Hospital Indemnity | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		821	836
Hospital Indemnity | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		821	836
Dental/Vision | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		260	272
Dental/Vision | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		260	272
Other | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		3,875	4,090
Other | Aflac Japan | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		3,875	4,090
Other | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		514	521
Other | Aflac U.S. | Operating Segments
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 514	$ 521

[1] Elimination entry necessary due to the internal reinsurance transactions with Aflac Re and to recapture a portion of policy liabilities ceded externally as a result of the reinsurance retrocession transaction. See Note 8 of the Notes to the Consolidated Financial Statements in the 2023 Annual Report.