STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Capital and Surplus Based on Statutory Accounting Practices (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Aflac
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	$ 3,097	$ 2,627
CAIC
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	360	244
TOIC
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	60	57
Aflac New York
Statutory Accounting Practices [Line Items]
Capital and surplus, NAIC basis	$ 339	$ 360