POLICY LIABILITIES - Schedule of Other Policyholders' Funds by Guaranteed Crediting Rates (Details) - USD ($) $ in Millions		Mar. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance, Weighted Average Crediting Rate		1.50%	1.50%
Aflac Japan | Fixed Annuity
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
At Guaranteed Minimum	[1]	$ 5,494	$ 5,221	$ 5,939
Cash Surrender Value	[1]	$ 5,420	$ 5,150
Lower Limit | Aflac Japan | Fixed Annuity
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Guaranteed Minimum Crediting Rates	[1],[2]	0.50%	0.50%
Upper Limit | Aflac Japan | Fixed Annuity
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Guaranteed Minimum Crediting Rates	[1],[2]	2.20%	2.20%

[1] Aflac Japan fixed annuities

[2] Weighted-average crediting rate of 1.5% at March 31, 2025 and December 31, 2024.