Description of Business and Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Nature of Operations	Healthcare Services Group, Inc. (the “Company”) provides management, administrative and operating expertise and services to the housekeeping, laundry, linen, facility maintenance and dietary service departments of the health care industry, including nursing homes, retirement complexes, rehabilitation centers and hospitals located throughout the United States. Although we do not directly participate in any government reimbursement programs, our clients’ reimbursements are subject to government regulation. Therefore, they are directly affected by any legislation relating to Medicare and Medicaid reimbursement programs. We provide our services primarily pursuant to full service agreements with our clients. In such agreements, we are responsible for the day-to-day management of employees located at our clients’ facilities. We also provide services on the basis of management-only agreements for a limited number of clients. Our agreements with clients typically provide for renewable one year service terms, cancelable by either party upon 30 to 90 days notice after the initial 60 to 120 day period. We are organized into two reportable segments: housekeeping, laundry, linen and other services (“Housekeeping”), and dietary department services (“Dietary”). Housekeeping consists of the managing of clients’ housekeeping departments, which are principally responsible for the cleaning, disinfecting and sanitizing of patient rooms and common areas of a client’s facility, as well as the laundering and processing of the personal clothing belonging to the facility’s patients. Also within the scope of this segment’s service is the responsibility for laundering and processing of bed linens, uniforms and other assorted linen items utilized by a client facility. Dietary consists of managing clients’ dietary department which is principally responsible for food purchasing, meal preparation and providing dietitian consulting professional services, which includes the development of a menu that meets patients’ dietary needs.
Unaudited Interim Financial Data	The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“US GAAP”) for interim financial information and the requirements of Form 10-Q and Article 10 of Regulation S-X. Accordingly, these consolidated financial statements do not include all of the information and footnotes necessary for a complete presentation of financial position, results of operations and cash flows. However, in our opinion, all adjustments which are of a normal recurring nature and necessary for a fair presentation have been reflected in these consolidated financial statements. The balance sheet shown in this report as of December 31, 2015 has been derived from, and does not include, all of the disclosures contained in the financial statements for the year ended December 31, 2015. These financial statements should be read in conjunction with the financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2015. The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for any future period.
Principles of Consolidation	The accompanying consolidated financial statements include the accounts of Healthcare Services Group, Inc. and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated in consolidation.
Cash and Cash Equivalents	Cash and cash equivalents are held in U.S. financial institutions or in custodial accounts with U.S. financial institutions. Cash equivalents are defined as short-term, highly liquid investments with a maturity of three months or less at the time of purchase that are readily convertible into cash and have insignificant interest rate risk.
Inventories and Supplies	Inventories and supplies include housekeeping, linen and laundry supplies, as well as food provisions and supplies. Inventories and supplies are stated at cost to approximate a first-in, first-out (FIFO) basis. Linen supplies are amortized on a straight-line basis over their estimated useful life of 24 months.
Revenue Recognition	Revenues from our service agreements with clients are recognized as services are performed. As a distributor of laundry equipment, we occasionally sell laundry installations to certain clients. The sales in most cases represent the construction and installation of a turn-key operation and have payment terms ranging from 24 to 60 months.
Income Taxes	We use the asset and liability method of accounting for income taxes. Under this method, income tax expense is recognized for the amount of taxes payable or refundable for the current period. We accrue for probable tax obligations as required by facts and circumstances in various regulatory environments. In addition, deferred tax assets and liabilities are recognized for expected future tax consequences of temporary differences between the book and tax bases of assets and liabilities. When appropriate, valuation allowances are recorded to reduce deferred tax assets to amounts for which realization is more likely than not. Uncertain income tax positions taken or expected to be taken in tax returns are reflected within our financial statements based on a recognition and measurement process.
Earnings per Common Share	Basic earnings per common share are computed by dividing income available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted earnings per common share are calculated using the weighted-average number of common shares outstanding and dilutive common shares, such as those issuable upon exercise of stock options.
Share-Based Compensation	The Company recognizes compensation expense for share-based awards and programs for employees and directors. We estimate the fair value of stock options as of the date of grant using a Black-Scholes option valuation model, while share-based awards are valued based on the market-price on the date of grant. The value of the portion of the award that is ultimately expected to vest, after accounting for forfeitures, is recognized as an expense in the Company’s consolidated statements of comprehensive income ratably over the requisite service periods.
Use of Estimates in Financial Statements	In preparing financial statements in conformity with U.S. GAAP, we make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities, and the reported amounts of revenues and expenses. Actual results could differ from those estimates. Significant estimates are used in determining, but are not limited to, our allowance for doubtful accounts, accrued insurance claims, asset valuations, deferred taxes and reviews for potential impairment. The estimates are based upon various factors including current and historical trends, as well as other pertinent industry and regulatory authority information. We regularly evaluate this information to determine if it is necessary to update the basis for our estimates and to adjust for known changes.
Self-Funded Captive Insurance Programs	In 2015, the Company transitioned its workers compensation and certain employee health & welfare insurance programs to HCSG Insurance Corp. (“HCSG Insurance”), its wholly owned captive insurance subsidiary which previously provided only general liability coverage to the Company. HCSG Insurance was formed to provide the Company with greater efficiency in managing its property & casualty and health & welfare programs.
Concentrations of Credit Risk	Our financial instruments consist principally of cash and cash equivalents, marketable securities, deferred compensation funding and accounts and notes receivable. Our marketable securities are fixed income investments which are highly liquid and can be readily purchased or sold through established markets. At September 30, 2016 and December 31, 2015, substantially all of our cash and cash equivalents and marketable securities were held in one large financial institution located in the United States. Our clients are concentrated in the health care industry and are primarily providers of long-term care. Many of our clients’ revenues are highly reliant on Medicare, Medicaid and third party payors’ reimbursement funding rates. Legislation can significantly alter overall government reimbursement for nursing home services and such changes, as well as other trends in the long-term care industry, have affected and could adversely affect the liquidity of our clients, resulting in their inability to make payments to us in accordance with agreed upon payment terms. These factors could result in the recognition of significant additional bad debts in the future.
Recent Accounting Pronouncements	In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments. The update replaces the current incurred loss impairment methodology of recognizing credit losses with a methodology that instead reflects expected credit losses and requires consideration of a broader range of information to inform credit loss estimates. The standard is effective for fiscal years beginning after December 15, 2019, including interim periods within those years, with early adoption permitted for fiscal years and interim periods beginning after December 15, 2018. The Company is in the process of evaluating the impact of the adoption of this ASU. In March 2016, the FASB issued ASU 2016-09, Stock Compensation: Improvements to Employee Share-Based Payment Accounting. ASU 2016-09 is intended to simplify several aspects of the accounting for share-based payments. The guidance will be effective for fiscal years beginning after December 15, 2016, including interim periods within that year. The Company is in the process of evaluating the impact of the adoption of this ASU. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, and a subsequent amendment to the standard in March 2016 with ASU 2016-08. The original standard provides guidance on recognizing revenue, including a five step model to determine when revenue recognition is appropriate. The standard requires that an entity recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendment to the standard clarifies implementation guidance on principal versus agent considerations. Adoption of the new standard is effective for reporting periods beginning after December 15, 2017, with early adoption prohibited. The Company is in the process of evaluating the impact of the adoption of this ASU. In February 2016, the FASB issued ASU 2016-02, Leases. ASU 2016-02 requires lessees to recognize assets and liabilities on their balance sheet related to the rights and obligations created by most leases, while continuing to recognize expenses on their income statements over the lease term. It will also require disclosures designed to give financial statement users information regarding the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. Early adoption is permitted for all entities. The Company is currently evaluating the impact ASU 2016-02 will have on our consolidated financial statements and associated disclosures. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes. The amendment in this ASU requires that deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent in a classified statement of financial position. The guidance becomes effective for annual reporting periods beginning after December 15, 2016 with early adoption permitted. Management elected to adopt the standard in the first quarter of 2016, with retrospective application to prior period balances presented. The adoption of ASU 2015-17 did not have a material impact on the Company’s consolidated financial statements.