Description of Business and Significant Accounting Policies - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Notes receivable	$ 6.9	$ 5.7
Discounted notes receivable	$ 6.8	$ 5.7

Notes receivable amounts discounted to present value due to impaired status.

No definition available.

Name:	hcsg_NotesReceivableImpairedNonperforming
Namespace Prefix:	hcsg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant