SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Common Stock Issued [Roll Forward]
Balance, beginning of period	1,351,018	1,349,309
Exercise of stock options and issuance of restricted shares	1,544	1,546
Balance, end of period	1,352,562	1,350,855
Treasury Stock [Roll Forward]
Balance, beginning of period	658,564	622,516
Balance, end of period	689,745	647,281
Shares outstanding, end of period	662,817	703,574
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired under share repurchase program, shares	32,186	26,108
Other purchases	419	541
Shares issued to AFL Stock Plan	(967)	(1,584)
Exercise of stock options	(240)	(49)
Other dispositions	(217)	(251)