SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		$ 9,034	$ 8,758	$ 9,132
Future policy benefits & unpaid policy claims		62,815	70,762
Unearned premiums		1,323	1,286
Other policyholders’ funds		5,445	5,460
Net earned premiums	[1]	13,548	13,440	14,123
Net investment income		4,076	4,116	3,811
Benefits and claims, net		7,293	7,450	8,211
Amortization of deferred policy acquisition costs		874	851	816
Other operating expenses		4,464	4,209	4,412
Premiums written		13,997	13,771	14,237
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		(5,167)	(5,905)
Unearned premiums		(8)	(38)
Other policyholders’ funds		0	0
Aflac Japan
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		5,302	5,102
Future policy benefits & unpaid policy claims		52,602	60,890
Unearned premiums		1,245	1,199
Other policyholders’ funds		5,445	5,460
Net earned premiums		6,744	6,930	8,047
Net investment income		2,854	3,032	3,033
Benefits and claims, net		3,999	4,317	5,313
Amortization of deferred policy acquisition costs		323	321	326
Other operating expenses		1,595	1,527	1,790
Premiums written		7,820	7,866	8,571
Aflac U.S.
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs		3,732	3,656
Future policy benefits & unpaid policy claims		11,281	10,960
Unearned premiums		97	103
Other policyholders’ funds		0	0
Net earned premiums		5,999	5,829	5,675
Net investment income		854	883	854
Benefits and claims, net		2,837	2,726	2,431
Amortization of deferred policy acquisition costs		551	530	490
Other operating expenses		2,094	2,064	2,201
Premiums written		6,177	5,905	5,666
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		4,099	4,817
Unearned premiums		(11)	22
Other policyholders’ funds		0	0
Net earned premiums		805	681	400
Net investment income		368	201	(77)
Benefits and claims, net		458	407	467
Amortization of deferred policy acquisition costs		0	0	0
Other operating expenses		775	618	421
Premiums written		$ 0	$ 0	$ 0

[1] Includes a gain (loss) of $(52), $(81) and $20 in 2025, 2024 and 2023, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.