Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail 1) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments and cash:
Available for sale, fixed maturity securities		$ 98,696	$ 105,882
Other investments		3,842	2,429
Cash and cash equivalents		5,051	5,141
Total investments and cash		142,978	149,753
Other assets		3,071	2,715
Assets		157,542	165,086
Liabilities:
Notes payable		7,839	7,745
Other Liabilities		4,760	3,612
Total liabilities		124,289	131,527
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2021 and 2020; issued 1,352,739 shares in 2021 and 1,351,018 shares in 2020		135	135
Additional paid-in capital		2,529	2,410
Retained earnings		41,381	37,984
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(2,013)	(1,109)
Unrealized gains (losses) on fixed maturity securities		9,602	10,361
Unrealized gains (losses) on derivatives		(30)	(34)
Pension liability adjustment		(166)	(284)
Treasury stock, at average cost		(18,185)	(15,904)
Total shareholders' equity		33,253	33,559	$ 28,959	$ 23,462
Total liabilities and shareholders' equity		157,542	165,086
Parent Company
Investments and cash:
Available for sale, fixed maturity securities		1,828	1,876
Investments in subsidiaries	[1]	35,905	36,217
Other investments		1,413	902
Cash and cash equivalents		2,097	2,126	$ 2,508	$ 1,767
Total investments and cash		41,243	41,121
Due from subsidiaries	[1]	248	253
Income taxes receivable		0	203
Other assets		640	368
Assets		42,131	41,945
Liabilities:
Employee benefit plans		336	340
Notes payable		7,579	7,456
Other Liabilities		963	590
Total liabilities		8,878	8,386
Shareholders' equity:
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2021 and 2020; issued 1,352,739 shares in 2021 and 1,351,018 shares in 2020		135	135
Additional paid-in capital		2,529	2,410
Retained earnings		41,381	37,984
Accumulated other comprehensive income (loss):
Unrealized foreign currency translation gains (losses)		(2,013)	(1,109)
Unrealized gains (losses) on fixed maturity securities		9,602	10,361
Unrealized gains (losses) on derivatives		(30)	(34)
Pension liability adjustment		(166)	(284)
Treasury stock, at average cost		(18,185)	(15,904)
Total shareholders' equity		33,253	33,559
Total liabilities and shareholders' equity		$ 42,131	$ 41,945

[1] Eliminated in consolidation