INVESTMENTS - Securities Lending (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Disclosure - Securities Lending [Abstract]
Security loans outstanding, fair value	$ 188	$ 812
Cash collateral on loaned securities	$ 193	$ 838

The cash or fair value of collateral received by the entity associated with securities borrowed that must be returned if the counterparty fulfills its obligations. It appears on the balance sheet as a liability and has a corresponding asset on the balance sheet, either cash or securities, depending on which was received as the collateral.

No definition available.

Name:	afl_ObligationToReturnCashOrSecuritiesReceivedAsCollateral
Namespace Prefix:	afl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant