SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		$ 8,758	$ 9,132	$ 9,239
Future policy benefits & unpaid policy claims		70,762	83,979
Unearned premiums		1,286	1,451
Other policyholders’ funds		5,460	6,169
Net earned premiums	[1]	13,440	14,123	14,901
Net investment income		4,116	3,811	3,656
Benefits and claims, net		7,450	8,211	8,887
Amortization of deferred policy acquisition costs		851	816	792
Other operating expenses		4,209	4,412	4,592
Premiums written		13,771	14,237	14,943
Intercompany eliminations
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		0	0
Future policy benefits & unpaid policy claims		(5,905)	(5,121)
Unearned premiums		(38)	(26)
Other policyholders’ funds		0	0
Aflac Japan
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		5,102	5,559
Future policy benefits & unpaid policy claims		60,890	73,641
Unearned premiums		1,199	1,358
Other policyholders’ funds		5,460	6,169
Net earned premiums		6,930	8,047	9,186
Net investment income		3,032	3,033	2,867
Benefits and claims, net		4,317	5,313	6,191
Amortization of deferred policy acquisition costs		321	326	338
Other operating expenses		1,527	1,790	2,080
Premiums written		7,866	8,571	9,474
Aflac U.S.
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		3,656	3,573
Future policy benefits & unpaid policy claims		10,960	11,492
Unearned premiums		103	107
Other policyholders’ funds		0	0
Net earned premiums		5,829	5,675	5,570
Net investment income		883	854	759
Benefits and claims, net		2,726	2,431	2,555
Amortization of deferred policy acquisition costs		530	490	455
Other operating expenses		2,064	2,201	2,117
Premiums written		5,905	5,666	5,469
Corporate and other
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		0	0
Future policy benefits & unpaid policy claims		4,817	3,967
Unearned premiums		22	12
Other policyholders’ funds		0	0
Net earned premiums		681	400	145
Net investment income		201	(77)	30
Benefits and claims, net		407	467	141
Amortization of deferred policy acquisition costs		0	0	0
Other operating expenses		618	421	395
Premiums written		$ 0	$ 0	$ 0

[1] Includes a gain (loss) of $(81), $20 and $(42) in 2024, 2023 and 2022, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.