v3.26.1
DEFERRED POLICY ACQUISITION COSTS - Schedule Of Deferred Policy Acquisition Costs (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     $ 9,034 $ 8,758 $ 8,758
Capitalization     546   1,105
Amortization expense $ (218) $ (221) (439) (437) (874)
Foreign currency translation and other     (193)   45
Balance, end of period 8,948   8,948   9,034
Aflac Japan | Cancer          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     2,965 2,776 2,776
Capitalization     168   357
Amortization expense     (91)   (188)
Foreign currency translation and other     (109)   20
Balance, end of period 2,933   2,933   2,965
Aflac Japan | Medical and other health          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     1,840 1,833 1,833
Capitalization     49   85
Amortization expense     (45)   (99)
Foreign currency translation and other     (67)   21
Balance, end of period 1,777   1,777   1,840
Aflac Japan | Life insurance          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     446 441 441
Capitalization     23   33
Amortization expense     (16)   (33)
Foreign currency translation and other     (16)   5
Balance, end of period 437   437   446
Aflac Japan | Other          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     51 52 52
Capitalization     1   3
Amortization expense     (2)   (3)
Foreign currency translation and other     (1)   (1)
Balance, end of period 49   49   51
Aflac U.S. | Life insurance          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     277 219 219
Capitalization     62   98
Amortization expense     (24)   (40)
Foreign currency translation and other     0   0
Balance, end of period 315   315   277
Aflac U.S. | Accident          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     909 915 915
Capitalization     64   137
Amortization expense     (73)   (143)
Foreign currency translation and other     0   0
Balance, end of period 900   900   909
Aflac U.S. | Disability          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     641 636 636
Capitalization     58   127
Amortization expense     (61)   (122)
Foreign currency translation and other     0   0
Balance, end of period 638   638   641
Aflac U.S. | Critical care          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     1,355 1,348 1,348
Capitalization     75   162
Amortization expense     (81)   (155)
Foreign currency translation and other     0   0
Balance, end of period 1,349   1,349   1,355
Aflac U.S. | Hospital indemnity          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     463 452 452
Capitalization     40   90
Amortization expense     (40)   (79)
Foreign currency translation and other     0   0
Balance, end of period 463   463   463
Aflac U.S. | Dental/vision          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     87 86 86
Capitalization     6   13
Amortization expense     (6)   (12)
Foreign currency translation and other     0   0
Balance, end of period 87   87   87
Aflac U.S. | Other          
Deferred Policy Acquisition Cost [Line Items]          
Balance, beginning of period     0 $ 0 0
Capitalization     0   0
Amortization expense     0   0
Foreign currency translation and other     0   0
Balance, end of period $ 0   $ 0   $ 0