Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail 1) - USD ($) $ in Millions		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments and cash:
Fixed maturity securities, available-for-sale		$ 65,269	$ 73,290
Other investments		5,958	4,530
Cash and cash equivalents		6,229	4,306
Total investments and cash		105,087	113,560
Other assets		1,845	2,008
Assets		117,566	126,724
Liabilities:
Notes payable and lease obligations		7,498	7,364
Other Liabilities		3,852	4,119
Total liabilities		91,468	104,739
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2024 and 2023; issued 1,356,763 shares in 2024 and 1,355,398 shares in 2023		136	136
Additional paid-in capital		2,894	2,771
Retained earnings		52,277	47,993
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(4,998)	(4,069)
Unrealized gains (losses) on fixed maturity securities		24	1,139
Unrealized gains (losses) on derivatives		(20)	(22)
Effect of changes in discount rate assumptions		2,006	(2,560)
Pension liability adjustment		10	(8)
Treasury stock, at average cost		(26,231)	(23,395)
Total shareholders’ equity		26,098	21,985	$ 20,140	$ 17,031
Total liabilities and shareholders' equity		117,566	126,724
Parent Company
Investments and cash:
Fixed maturity securities, available-for-sale		1,713	1,582
Investments in subsidiaries	[1]	27,890	24,508
Other investments		1,239	1,126
Cash and cash equivalents		2,308	1,007	$ 1,143	$ 2,097
Total investments and cash		33,150	28,223
Due from subsidiaries	[1]	242	270
Income taxes receivable		71	251
Other assets		1,121	1,202
Assets		34,584	29,946
Liabilities:
Employee benefit plans		347	329
Notes payable and lease obligations		7,219	6,819
Other Liabilities		920	813
Total liabilities		8,486	7,961
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2024 and 2023; issued 1,356,763 shares in 2024 and 1,355,398 shares in 2023		136	136
Additional paid-in capital		2,894	2,771
Retained earnings		52,277	47,993
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(4,998)	(4,069)
Unrealized gains (losses) on fixed maturity securities		24	1,139
Unrealized gains (losses) on derivatives		(20)	(22)
Effect of changes in discount rate assumptions		2,006	(2,560)
Pension liability adjustment		10	(8)
Treasury stock, at average cost		(26,231)	(23,395)
Total shareholders’ equity		26,098	21,985
Total liabilities and shareholders' equity		$ 34,584	$ 29,946

[1] Eliminated in consolidation