SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Common Stock Issued [Roll Forward]
Balance, beginning of period	1,349,309	1,347,540
Exercise of stock options and issuance of restricted shares	1,426	1,504
Balance, end of period	1,350,735	1,349,044
Treasury Stock [Roll Forward]
Balance, beginning of period	622,516	592,254
Balance, end of period	636,827	608,579
Shares outstanding, end of period	713,908	740,465
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired under share repurchase program, shares	15,193	17,179
Other purchases	521	574
Shares issued to AFL Stock Plan	(1,116)	(836)
Exercise of stock options	(45)	(305)
Other dispositions	(242)	(287)