v3.25.2
POLICY LIABILITIES - Summary of Net Earned Premiums Recognized (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Liability for Future Policy Benefit, Activity [Line Items]        
Reinsurance ceded $ (91) $ (66) $ (179) $ (135)
Net earned premiums [1] 3,470 3,325 6,851 6,781
Aflac Japan | Cancer        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 885 832 1,724 1,710
Aflac Japan | Medical and other health        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 557 570 1,086 1,175
Aflac Japan | Life insurance        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 328 316 644 655
Aflac Japan | Other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 33 35 65 69
Aflac U.S. | Life insurance        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 170 141 339 279
Aflac U.S. | Accident        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 309 316 620 641
Aflac U.S. | Disability        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 354 332 706 665
Aflac U.S. | Critical Care        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 443 441 884 885
Aflac U.S. | Hospital Indemnity        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 183 182 367 367
Aflac U.S. | Dental/Vision        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 52 46 101 105
Aflac U.S. | Other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 41 25 90 45
Corporate and other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums $ 206 $ 155 $ 404 $ 320
[1] Includes a gain (loss) of an immaterial amount and $(2) for the three-month periods and an immaterial amount and $(5) for the six-month periods ended June 30, 2025 and 2024, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.