CONTINGENCIES (Details)	Mar. 31, 2012 proceeding
CONTINGENCIES
Minimum number of proceedings that could have a material impact	1

The minimum number of proceedings that could have a material adverse affect on the Company's results of operations for the periods in which a loss is recognized.

No definition available.

Name:	mjn_LossContingencyNumberOfProceedingsThatCouldHaveAMaterialAdverseAffectMinimum
Namespace Prefix:	mjn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant