BUSINESS SEGMENT AND FOREIGN INFORMATION - Information on Transfers of Funds from Aflac Japan (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting [Abstract]
Management fees	$ 53	$ 39	$ 37
Allocated expenses	101	71	74
Profit repatriation	2,139	1,704	771
Total transfers from Aflac Japan	$ 2,293	$ 1,814	$ 882