POLICY LIABILITIES - Reconciliation of Future Policy Benefits (Detail) - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 62,320	$ 70,381
Deferred reinsurance gain liability		125	146
Intercompany eliminations
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	[1]	(4,997)	(5,760)
Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Deferred profit liability		2,066	1,844
Deferred reinsurance gain liability		757	806
Aflac Japan | Cancer
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		22,780	26,597
Aflac Japan | Medical and other health
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		7,343	8,789
Aflac Japan | Life insurance
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		16,347	19,109
Aflac Japan | Other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		2,946	3,379
Aflac U.S. | Life insurance
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		1,055	938
Aflac U.S. | Accident
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		659	630
Aflac U.S. | Disability
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		651	695
Aflac U.S. | Critical care
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		6,900	6,800
Aflac U.S. | Hospital indemnity
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		784	775
Aflac U.S. | Dental/vision
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		236	245
Aflac U.S. | Other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		476	462
Corporate and other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 4,317	$ 5,072

[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 for additional details