STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Profit Remittances by Aflac Japan (Detail) $ in Millions, ¥ in Billions	12 Months Ended
Dec. 31, 2023 USD ($)	Dec. 31, 2023 JPY (¥)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 JPY (¥)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 JPY (¥)
Insurance [Abstract]
Profit remittances	$ 2,623	¥ 374.7	$ 2,412	¥ 324.2	$ 2,138	¥ 236.7

Amount of foreign earnings repatriated from subsidiaries outside the country of domicile.

No definition available.

Name:	us-gaap_ForeignEarningsRepatriated
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration