v3.26.3
BUSINESS SEGMENT INFORMATION - Additional Information (Details)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
USD ($)
Sep. 30, 2025
USD ($)
Sep. 30, 2026
USD ($)
segment
Sep. 30, 2025
USD ($)
Dec. 31, 2025
Segment Reporting [Line Items]          
Number of reportable insurance business segments | segment     2    
Net earned premiums [1] $ 3,304 $ 3,372 $ 9,866 $ 10,223  
Aflac Re Bermuda Ltd. (Aflac Re)          
Segment Reporting [Line Items]          
Net earned premiums $ 230 $ 173 $ 540 $ 529  
Aflac Japan          
Segment Reporting [Line Items]          
Percentage of the Company's total revenues 50.00% 53.00% 51.00% 53.00%  
Percentage of the Company's total assets 77.00%   77.00%   76.00%
[1] Includes a gain (loss) of $52 and $(55) for the three-month periods and $52 and $(55) for the nine-month periods ended September 30, 2026 and 2025, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.