POLICY LIABILITIES - Reconciliation of Future Policy Benefits (Details) - USD ($) $ in Millions		Mar. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 77,867	$ 83,718
Deferred reinsurance gain liability		161	175
Deferred Profit Liability - Limited-payment Contracts
Liability for Future Policy Benefit, Activity [Line Items]
Deferred profit liability - limited-payment contracts		1,734	1,806
Deferred reinsurance gain liability		910	1,012
Intercompany eliminations
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits	[1]	(4,598)	(5,017)
Corporate and other
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		3,842	4,225
Cancer | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		30,172	32,652
Medical and other health | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		9,806	10,560
Life insurance | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		21,348	23,243
Life insurance | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		901	911
Accident | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		611	621
Disability | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		757	770
Critical Care | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		7,021	7,216
Hospital Indemnity | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		811	836
Dental/Vision | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		266	272
Other | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		3,777	4,090
Other | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Future policy benefits		$ 509	$ 521

[1] Elimination entry necessary due to the internal reinsurance transactions with Aflac Re and to recapture a portion of policy liabilities ceded externally as a result of the reinsurance retrocession transaction. See Note 8 for additional details.