COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Details) - Management Consulting and Technology Services Company Application Maintenance and Development Services - Aflac Japan $ in Millions, ¥ in Billions	9 Months Ended
	Sep. 30, 2023 JPY (¥)	Sep. 30, 2023 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreement, remaining term	5 years	5 years
Outsourcing agreement, aggregate remaining cost	¥ 19.2	$ 128