Note 6 - Estimated Liability for Appeals (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Estimated Liability for Appeals	$ 31,544	$ 30,755
Estimated Liability for Appeals, Amount Adjudicated	17,900	17,300
Estimated Liability for Appeals, Amount Probable of Being Returned	$ 10,600	$ 11,100

Liability as of the balance sheet date for the estimated liability for appeals and estimated allowance for appeals related to receivables associated with client contracts that have be received on or before the balance sheet date.

No definition available.

Name:	hmsy_EstimatedLiabilityForAppeals
Namespace Prefix:	hmsy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant