Revenue Recognition (Details)	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012
Revenue Recognition
Percentage of revenues from governmental healthcare programs	25.00%	28.00%

Percent healthcare revenues governmental programs.

No definition available.

Name:	amsg_PercentHealthcareRevenuesGovernmentalPrograms
Namespace Prefix:	amsg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration