Schedule II - Valuation and Qualifying Accounts and Reserves (Details) - Allowance For Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$ 11,985	$ 6,911	$ 4,608
Additions
Charged to Costs and Expenses	51,387	6,250	4,629
Charged to Other Accounts	0	0	0
Deductions	6,163	1,176	2,326
Ending Balance	$ 57,209	$ 11,985	$ 6,911

Valuation Allowances and Reserves, Additions [Abstract]

No definition available.

Name:	hcsg_ValuationAllowancesandReservesAdditionsAbstract
Namespace Prefix:	hcsg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivableRollforward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of valuation and qualifying accounts and reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense.

+ References

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of decrease in valuation and qualifying accounts and reserves.

+ References

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForCreditLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: