STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Aflac Re Bermuda
Statutory Accounting Practices [Line Items]
Capital and surplus, statutory accounting practices of the state or country basis	$ 581.0	$ 439.0
Dividends declared	0.0	0.0
Statutory Accounting Practices, Minimum Margin of Solvency, Assets Threshold	$ 0.5
Statutory Accounting Practices, Minimum Margin of Solvency, Percentage of Assets in Excess of Threshold	1.50%
Statutory Accounting Practices, Minimum Margin of Solvency, Percentage of Enhanced Capital Requirement	25.00%
Aflac
Statutory Accounting Practices [Line Items]
Dividends declared	$ 976.0	894.0
Amount available for dividend distribution without prior approval from regulatory agency	912.0
CAIC
Statutory Accounting Practices [Line Items]
Dividends declared	0.0	0.0
TOIC
Statutory Accounting Practices [Line Items]
Dividends declared	0.0	0.0
Aflac New York
Statutory Accounting Practices [Line Items]
Dividends declared	54.0	67.0
Aflac Japan
Statutory Accounting Practices [Line Items]
Capital and surplus, statutory accounting practices of the state or country basis	$ 8,100.0	$ 8,100.0