SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares shares in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 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	1,299	1,576
Balance, end of period	1,347,061	1,344,074
Treasury Stock [Roll Forward]
Balance, beginning of period	564,852	530,877
Balance, end of period	577,789	552,077
Shares outstanding, end of period	769,272	791,997
Treasury Stock
Treasury Stock [Roll Forward]
Stock acquired in open market, shares	13,441	22,310
Other purchases	328	346
Shares issued to AFL Stock Plan	(400)	(998)
Exercise of stock options	(327)	(414)
Other dispositions	(105)	(44)