v3.26.1
POLICY LIABILITIES - Summary of Net Earned Premiums Recognized (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Liability for Future Policy Benefit, Activity [Line Items]        
Reinsurance ceded $ (136) $ (91) $ (271) $ (179)
Net earned premiums [1] 3,252 3,470 6,562 6,851
Aflac Japan | Cancer        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 796 885 1,612 1,724
Aflac Japan | Medical and other health        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 474 557 969 1,086
Aflac Japan | Life insurance        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 292 328 590 644
Aflac Japan | Other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 28 33 57 65
Aflac U.S. | Life insurance        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 196 170 394 339
Aflac U.S. | Accident        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 303 309 608 620
Aflac U.S. | Disability        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 372 354 746 706
Aflac U.S. | Critical care        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 441 443 885 884
Aflac U.S. | Hospital indemnity        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 182 183 365 367
Aflac U.S. | Dental/vision        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 56 52 114 101
Aflac U.S. | Other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums 72 41 135 90
Corporate and other        
Liability for Future Policy Benefit, Activity [Line Items]        
Gross premiums $ 176 $ 206 $ 358 $ 404
[1] Includes a gain (loss) of an immaterial amount for the three- and six-month periods ended June 30, 2026 and 2025, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.