v3.26.1
REINSURANCE - Additional Information (Details) - USD ($)
$ in Millions
1 Months Ended
Mar. 31, 2026
Jan. 31, 2026
Jun. 30, 2026
Dec. 31, 2025
Effects of Reinsurance [Line Items]        
Deferred reinsurance gain liability     $ 282 $ 125
Reinsurance recoverable     444 161
Reinsurance recoverable, allowance for credit losses     $ 17 $ 4
Aflac Re Bermuda Ltd. (Aflac Re)        
Effects of Reinsurance [Line Items]        
Assumed reinsurance, amount of reserves assumed $ 551      
Assumed reinsurance, amount of assets received $ 636      
Reinsurer, Other | Aflac Life Insurance Japan Ltd. (ALIJ)        
Effects of Reinsurance [Line Items]        
Ceded reinsurance, percentage   100.00%    
Ceded reinsurance, amount of reserves transferred   $ 333    
Ceded reinsurance, amount of assets transferred   $ 236