BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 121,307	$ 131,094	$ 116,237
Aflac Japan
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	102,973	113,678	101,692
Aflac U.S.
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	16,112	16,122	13,942
Other business segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	155	154	160
Total Business Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	119,240	129,954	115,794
Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	19,909	20,318	16,182
Intercompany eliminations
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ (17,842)	$ (19,178)	$ (15,739)