Commitment and Contingencies (Details) (Unfavorable Regulatory Action [Member])	12 Months Ended
Dec. 31, 2011
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Loss Contingency Range Of Possible Loss Maximum Percent	1.00%

Loss Contingency, Range Of Possible Loss (Maximum) as a Percent of Total Worldwide Revenues.

No definition available.

Name:	mmsi_LossContingencyRangeOfPossibleLossMaximumPercent
Namespace Prefix:	mmsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration