INCOME TAXES - Income Tax Effects of Temporary Differences that Gave Rise to Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred income tax liabilities:
Deferred policy acquisition costs	$ 2,637	$ 2,883
Unrealized gains and other basis differences on investments	615	988
Foreign currency gain on Aflac Japan	1	2
Premiums receivable	43	85
Policy benefit reserves	2,509	110
Other	54	0
Total deferred income tax liabilities	5,859	4,068
Deferred income tax assets:
Unfunded retirement benefits	4	5
Other accrued expenses	32	28
Policy and contract claims	514	572
Deferred compensation	31	45
Depreciation	255	265
Anticipatory foreign tax credit	3,262	2,210
Deferred foreign tax credit and carryforward	1,428	1,077
Other	0	135
Total deferred income tax assets	5,526	4,337
Net deferred tax asset		(269)
Net deferred tax liability	333
Current income tax liability	240	423
Total income tax liability	$ 573	$ 154