Reconciliation of Number of Shares of Common Stock (Detail)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders Equity Note [Line Items]
Balance, beginning of period	662,660,000
Balance, end of period	663,639,000	662,660,000
Open market	6,000,000	2,000,000
Exercise of stock options	1,008,000	3,066,000	1,978,000
Shares outstanding, end of period	466,310,000	469,661,000	468,568,000
Common Stock
Stockholders Equity Note [Line Items]
Balance, beginning of period	662,660,000	661,209,000	660,035,000
Exercise of stock options and issuance of restricted shares	979,000	1,451,000	1,174,000
Balance, end of period	663,639,000	662,660,000	661,209,000
Treasury Stock
Stockholders Equity Note [Line Items]
Balance, beginning of period	192,999,000	192,641,000	193,420,000
Open market	6,000,000	2,000,000	0
Other	182,000	192,000	264,000
Shares issued to AFL Stock Plan	(1,690,000)	0	(355,000)
Exercise of stock options	(88,000)	(1,752,000)	(556,000)
Other	(74,000)	(82,000)	(132,000)
Balance, end of period	197,329,000	192,999,000	192,641,000