STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Capital and Surplus Based on Statutory Accounting Practices (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Aflac
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	$ 2,881	$ 3,097
CAIC
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	398	360
TOIC
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	51	60
Aflac New York
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	$ 323	$ 339