SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	$ 8,798				$ 9,658				$ 8,798	$ 9,658
Future Policy Benefits & Unpaid Policy Claims	72,899				80,497				72,899	80,497
Unearned premiums	10,642				11,904				10,642	11,904
Other policyholders' funds	5,861				5,319				5,861	5,319
Net premium revenue	4,910	5,028	5,013	5,184	5,643	5,660	5,467	5,378	20,135	22,148	20,362
Net investment income	826	821	813	833	876	869	845	882	3,293	3,473	3,280
Benefits and claims, net									13,813	15,330	13,749
Amortization of deferred policy acquisition costs									1,074	1,117	1,033
Other Operating Expenses									4,236	4,615	4,439
Premiums Written									21,104	28,650	23,767
Aflac Japan
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	5,819				6,801				5,819	6,801
Future Policy Benefits & Unpaid Policy Claims	64,122				72,286				64,122	72,286
Unearned premiums	10,520				11,779				10,520	11,779
Other policyholders' funds	5,660				5,118				5,660	5,118
Net premium revenue									14,982	17,151	15,619
Net investment income									2,651	2,845	2,688
Benefits and claims, net									10,924	12,496	11,037
Amortization of deferred policy acquisition costs									641	716	650
Other Operating Expenses									2,495	2,937	2,837
Premiums Written									15,960	23,662	19,034
Aflac U.S.
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	2,979				2,857				2,979	2,857
Future Policy Benefits & Unpaid Policy Claims	8,775				8,209				8,775	8,209
Unearned premiums	122				125				122	125
Other policyholders' funds	201				201				201	201
Net premium revenue									5,153	4,996	4,743
Net investment income									632	613	588
Benefits and claims, net									2,889	2,834	2,713
Amortization of deferred policy acquisition costs									433	400	383
Other Operating Expenses									1,431	1,397	1,341
Premiums Written									5,144	4,988	4,733
All Other
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	0				0				0	0
Future Policy Benefits & Unpaid Policy Claims	2				2				2	2
Unearned premiums	0				0				0	0
Other policyholders' funds	0				0				0	0
Net premium revenue									0	1	0
Net investment income									10	15	4
Benefits and claims, net									0	0	(1)
Amortization of deferred policy acquisition costs									0	1	0
Other Operating Expenses									310	281	261
Premiums Written									$ 0	$ 0	$ 0