BUSINESS SEGMENT AND SELECTED FOREIGN CURRENCY TRANSLATION ITEMS - Additional Information (Detail) $ in Millions		12 Months Ended
		Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of reportable insurance business segments | segment		2
Net earned premiums	[1]	$ 13,440	$ 14,123	$ 14,901
Receivables		779	848
Premiums receivable, allowance for credit loss		108	92
Aflac Re Bermuda
Segment Reporting Information [Line Items]
Net earned premiums		$ 568	$ 258	$ 1
Aflac Japan
Segment Reporting Information [Line Items]
Percentage of the Company's total revenues		55.00%	60.00%	64.00%
Percentage of the Company's total assets		77.00%	80.00%
Net earned premiums		$ 6,930	$ 8,047	$ 9,186
Receivables		$ 197	$ 175
Percentage of total receivables related to Aflac Japan's operations		25.30%	20.70%

[1] Includes a gain (loss) of $(81), $20 and $(42) in 2024, 2023 and 2022, respectively, related to remeasurement of the deferred profit liability for limited-payment contracts.