BUSINESS SEGMENT AND SELECTED FOREIGN CURRENCY TRANSLATION ITEMS - Operations by Segment - Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 117,566	$ 126,724
Aflac Japan
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	90,210	101,541
Aflac U.S.
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	21,930	21,861
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 5,426	$ 3,322