POLICY LIABILITIES - Liability for Future Policy Benefits (Detail) - USD ($) $ in Millions		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts		$ 80,749	$ 90,588
Intercompany eliminations
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts	[1]	$ (367)	$ (456)
Liability for future policy benefits, interest rate		2.00%
Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		3.00%	3.10%	3.10%
Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		5.00%	5.10%	5.20%
Health insurance | Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts		$ 42,936	$ 49,421
Health insurance | Aflac Japan | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		0.60%
Health insurance | Aflac Japan | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		6.75%
Health insurance | Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts		$ 8,972	8,949
Health insurance | Aflac U.S. | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		3.00%
Health insurance | Aflac U.S. | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		8.00%
Life insurance | Aflac Japan
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts		$ 28,218	31,756
Life insurance | Aflac Japan | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		0.60%
Life insurance | Aflac Japan | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		4.00%
Life insurance | Aflac U.S.
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability amounts		$ 990	$ 918
Life insurance | Aflac U.S. | Lower Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		2.50%
Life insurance | Aflac U.S. | Upper Limit
Liability for Future Policy Benefit, by Product Segment [Line Items]
Liability for future policy benefits, interest rate		6.00%

[1] Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements