Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Legal Fees In Responding to Department Of Justice Inquiry	$ 3.7	$ 8.5

Legal Fees In Responding to Department Of Justice Inquiry

No definition available.

Name:	mmsi_LegalFeesInRespondingtoDepartmentOfJusticeInquiry
Namespace Prefix:	mmsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration