SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Common Stock Issued [Roll Forward]
Balance, beginning of period	1,347,540	1,345,762
Exercise of stock options and issuance of restricted shares	1,504	1,299
Balance, end of period	1,349,044	1,347,061
Treasury Stock [Roll Forward]
Balance, beginning of period	592,254	564,852
Balance, end of period	608,579	577,789
Shares outstanding, end of period	740,465	769,272
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired under share repurchase program, shares	17,179	13,441
Other purchases	574	328
Shares issued to AFL Stock Plan	(836)	(400)
Exercise of stock options	(305)	(327)
Other dispositions	(287)	(105)