SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Common Stock Issued [Roll Forward]
Balance, beginning of period	1,345,762	1,342,498
Exercise of stock options and issuance of restricted shares	1,014	868
Balance, end of period	1,346,776	1,343,366
Treasury Stock [Roll Forward]
Balance, beginning of period	564,852	530,877
Balance, end of period	571,019	547,361
Shares outstanding, end of period	775,757	796,005
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired in open market, shares	6,640	16,986
Other purchases	315	288
Shares issued to AFL Stock Plan	(384)	(494)
Exercise of stock options	(305)	(256)
Other dispositions	(99)	(40)