INCOME TAXES - Income Tax Effects of Temporary Differences that Gave Rise to Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Deferred income tax liabilities:
Deferred policy acquisition costs	$ 2,695	$ 2,637
Unrealized gains and other basis differences on investments	0	615
Foreign currency gain on Aflac Japan	0	1
Premiums receivable	36	43
Policy benefit reserves	6,585	2,509
Other	237	54
Total deferred income tax liabilities	9,553	5,859
Deferred income tax assets:
Unfunded retirement benefits	4	4
Other accrued expenses	40	32
Policy and contract claims	504	514
Foreign currency loss on Aflac Japan	7	0
Deferred compensation	0	31
Depreciation	295	255
Anticipatory foreign tax credit	4,966	3,262
Deferred foreign tax credit and carryforward	1,098	1,428
Other basis differences in investments	1,360	0
Total deferred income tax assets	8,274	5,526
Net deferred income tax (asset) liability	1,279	333
Current income tax liability	89	240
Total income tax liability	$ 1,368	$ 573