STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Net Income (Loss) Based on Statutory Accounting Practices (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Aflac
Statutory Accounting Practices [Line Items]
Net income (loss), statutory accounting practices	$ 1,106	$ 1,134	$ 1,146
CAIC
Statutory Accounting Practices [Line Items]
Net income (loss), statutory accounting practices	(121)	(69)	(30)
TOIC
Statutory Accounting Practices [Line Items]
Net income (loss), statutory accounting practices	(27)	(35)	(27)
Aflac New York
Statutory Accounting Practices [Line Items]
Net income (loss), statutory accounting practices	$ 54	$ 67	$ 83