Related Party Transactions (Related Party Payments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Related Party Transactions
Operating leases	$ 29,240	$ 29,079	$ 29,137
Salaries and benefits	72,892	65,908	64,830
Billing fees	11,591	11,126	11,240
Medical advisory services	$ 2,993	$ 2,671	$ 2,575

Medical advisory service expenses recognized during the period resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

No definition available.

Name:	amsg_RelatedPartyTransactionMedicalAdvisoryServicesExpenseFromTransactionsWithRelatedParty
Namespace Prefix:	amsg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant