POLICY LIABILITIES - Additional Information (Details) - Health insurance - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Liability for Future Policy Benefit, by Product Segment [Line Items]
Prior years claims and claims adjustment expense	$ (151)	$ (215)	$ (512)	$ (739)
Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Prior years claims and claims adjustment expense			$ (321)
Percentage of total prior year claims and claims adjustment expense			63.00%
Liability for unpaid claims and claims adjustment expense, foreign currency translation gain (loss), prior year claims adjustment expense			$ (83)
Prior year claims and claims adjustment expense excluding effect of foreign currency			$ (404)
Percentage of total prior year claims and claims adjustment expense excluding effect of foreign currency			79.00%
Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Prior years claims and claims adjustment expense			$ (191)
Percentage of total prior year claims and claims adjustment expense			37.00%
Prior year claims and claims adjustment expense from refinement of estimates			$ (63)