SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs	$ 8,593	$ 9,525
Future policy benefits & unpaid policy claims	85,310	95,424
Unearned premiums	1,825	2,576
Other policyholders' funds	6,123	7,072
Net premium income	15,263	17,647	$ 18,622
Net investment income	3,656	3,818	3,638
Benefits and claims, net	9,153	10,576	11,796
Amortization of deferred policy acquisition costs	1,152	1,170	1,214
Other operating expenses	4,593	5,038	4,978
Premiums written	14,943	17,137	18,075
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	(667)	(733)
Unearned premiums	0	0
Other policyholders' funds	0	0
Aflac Japan
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs	5,355	6,233	6,991
Future policy benefits & unpaid policy claims	73,760	84,079
Unearned premiums	1,716	2,469
Other policyholders' funds	6,119	7,064
Net premium income	9,548	11,853	12,670
Net investment income	2,867	3,139	2,856
Benefits and claims, net	6,565	7,963	8,851
Amortization of deferred policy acquisition costs	547	653	644
Other operating expenses	2,083	2,555	2,613
Premiums written	9,474	11,600	12,312
Aflac U.S.
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]
Deferred policy acquisition costs	3,238	3,292	3,450
Future policy benefits & unpaid policy claims	11,912	11,798
Unearned premiums	113	111
Other policyholders' funds	4	8
Net premium income	5,570	5,614	5,758
Net investment income	759	752	702
Benefits and claims, net	2,442	2,447	2,765
Amortization of deferred policy acquisition costs	605	517	570
Other operating expenses	2,115	2,048	1,963
Premiums written	5,469	5,537	5,763
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	305	280
Unearned premiums	(4)	(4)
Other policyholders' funds	0	0
Net premium income	145	180	194
Net investment income	30	(73)	80
Benefits and claims, net	146	166	180
Amortization of deferred policy acquisition costs	0	0	0
Other operating expenses	395	435	402
Premiums written	$ 0	$ 0	$ 0