Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail 1) - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Investments and cash:
Fixed maturity securities, available-for-sale		$ 64,121	$ 65,269
Other investments		6,622	5,958
Cash and cash equivalents		6,245	6,229
Total investments and cash		103,760	105,087
Other assets		1,772	1,845
Total assets		116,470	117,566
Liabilities:
Notes payable and lease obligations		8,409	7,498
Other Liabilities		3,631	3,852
Total liabilities		86,980	91,468
Shareholders’ equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2025 and 2024; issued 1,357,909 shares in 2025 and 1,356,763 shares in 2024		136	136
Additional paid-in capital		3,024	2,894
Retained earnings		54,682	52,277
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(4,847)	(4,998)
Unrealized gains (losses) on fixed maturity securities		(1,809)	24
Unrealized gains (losses) on derivatives		(13)	(20)
Effect of changes in discount rate assumptions		8,035	2,006
Pension liability adjustment		86	10
Treasury stock, at average cost		(29,804)	(26,231)
Total shareholders’ equity		29,490	26,098	$ 21,985	$ 20,140
Total liabilities and shareholders’ equity		116,470	117,566
Parent Company
Investments and cash:
Fixed maturity securities, available-for-sale		1,714	1,713
Investments in subsidiaries	[1]	32,215	27,890
Other investments		978	1,239
Cash and cash equivalents		2,646	2,308	$ 1,007	$ 1,143
Total investments and cash		37,553	33,150
Due from subsidiaries	[1]	206	242
Income taxes receivable		147	71
Other assets		946	1,121
Total assets		38,852	34,584
Liabilities:
Employee benefit plans		357	347
Notes payable and lease obligations		8,143	7,219
Other Liabilities		862	920
Total liabilities		9,362	8,486
Shareholders’ equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2025 and 2024; issued 1,357,909 shares in 2025 and 1,356,763 shares in 2024		136	136
Additional paid-in capital		3,024	2,894
Retained earnings		54,682	52,277
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(4,847)	(4,998)
Unrealized gains (losses) on fixed maturity securities		(1,809)	24
Unrealized gains (losses) on derivatives		(13)	(20)
Effect of changes in discount rate assumptions		8,035	2,006
Pension liability adjustment		86	10
Treasury stock, at average cost		(29,804)	(26,231)
Total shareholders’ equity		29,490	26,098
Total liabilities and shareholders’ equity		$ 38,852	$ 34,584

[1] Eliminated in consolidation