BUSINESS SEGMENT INFORMATION - Operations by Segment - Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 130,626	$ 131,738
Aflac Japan
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	103,972	105,734
Aflac U.S.
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	20,932	21,002
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,722	$ 5,002