Operating Segments - Additional Information (Detail) (Americas, USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Americas
Segment Reporting Information [Line Items]
Americas royalty fees	$ 0.9	$ 0.7	$ 2.3	$ 1.3

Revenues From Transactions With Other Operating Segments of Entity

No definition available.

Name:	manh_RevenuesFromTransactionsWithOtherOperatingSegmentsOfEntity
Namespace Prefix:	manh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration