Organization and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Condensed Consolidated Financial Statements include our accounts and the accounts of our wholly-owned direct and indirect subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Our Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). In management's opinion, the unaudited Condensed Consolidated Financial Statements include all adjustments and accruals that are necessary for a fair presentation of the results of all interim periods reported herein and all such adjustments are of a normal, recurring nature. As a result of the adoption of Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers, and our application of the modified retrospective approach, prior period amounts have not been restated under ASC 606. Amounts shown on the Condensed Consolidated Statement of Operations within the operating expense categories of Cost of Revenue; Research and Development; Service, Rental and Maintenance; Selling and Marketing; and General and Administrative are recorded exclusive of depreciation, amortization and accretion. The financial information included herein, other than the Condensed Consolidated Balance Sheet as of December 31, 2017, is unaudited. The Condensed Consolidated Balance Sheet at December 31, 2017 has been derived from, but does not include all, the disclosures contained in the audited Consolidated Financial Statements as of and for the year ended December 31, 2017. These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and accompanying notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017 (the “2017 Annual Report”). The Condensed Consolidated Statement of Operations for the interim periods presented are not necessarily indicative of the results that may be expected for a full year.
Use of Estimates	Use of Estimates The preparation of these Condensed Consolidated Financial Statements requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues, expenses and related disclosures. On an on-going basis, we evaluate estimates and assumptions, including, but not limited to, those related to the impairment of long-lived assets; intangible assets subject to amortization and goodwill; accounts receivable allowances; revenue recognition; determining standalone selling price ("SSP") of performance obligations; variable consideration; depreciation expense; asset retirement obligations; severance and income taxes. We base our estimates on historical experience and various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
Revenue Recognition - Adoption of ASC 606 Revenue from Contracts with Customers	Revenue Recognition - Adoption of ASC 606 “Revenue from Contracts with Customers” The majority of our revenues are derived from short-term contracts related to the sale of wireless paging services and software solutions. Our arrangements exist primarily with customers in the healthcare market and to a lesser extent State and Federal governments, as well as large enterprise businesses. Under the typical payment terms of our software contracts customers will normally pay a material amount of the contract price immediately upon execution of the contract. The remaining payments are required when product is delivered, when services begin and, to a lesser extent, when services are completed. Wireless services are generally billed as incurred on a monthly basis. Our contracts will generally result in billings in excess of revenue recognized, which we present as deferred revenues on the Condensed Consolidated Balance Sheets, primarily due to the receipt of payment in advance of product or services being provided. Amounts billed and due from our customers are classified as receivables on the Condensed Consolidated Balance Sheet. At times, we may have contracts which require us to perform work or provide products prior to billing which will generally result in revenue recognized in excess of billings. This excess is presented as unbilled receivables in the Notes to the Condensed Consolidated Balance Sheets. We generally do not have transactions that include a significant financing component (whether payments are made in advance or in arrears) as our contracts typically take less than 12 months to complete once started. We account for a contract when: (1) both parties have approved the contract through mutually signed agreements but at times may be done through other methods such as purchase orders or master agreements; (2) the rights of the parties have been identified; (3) payment terms have been identified; (4) the contract has commercial substance; and (5) collectability of consideration is probable. We also evaluate whether two or more contracts should be combined and accounted for as a single contract. In our evaluation, we consider criteria such as, but not limited to, whether: (1) the contracts are negotiated as a package with a single commercial objective; (2) the amount of consideration to be paid in one contract is dependent on the price or performance of another contract; and (3) some or all of the goods or services promised in the contracts are a single performance obligation. Should we consider contracts related, we would account for those contracts as if they were a single contract. Evaluating whether two or more contracts should be combined and accounted for as a single contract requires significant judgment. In the aggregate, a decision to combine a group of contracts could significantly impact the amount of revenue and profit recorded in a given period. We review each contract to determine whether to account for the various promises as one or more performance obligations. The assessment and determination of performance obligations for a given contract requires significant judgment. Contracts which include wireless services are generally considered to be a single promise and therefore accounted for as a single performance obligation. Less commonly, however, we may promise to provide other distinct goods or services in conjunction with wireless services in which case we would account for the contract as having multiple performance obligations. Contracts which include goods or services related to our software solutions are generally sold with multiple promises and therefore will often include multiple performance obligations. Material performance obligations related to the sale of our software solutions include software licenses, professional services, hardware and maintenance, of which professional services and maintenance are generally considered a series of performance obligations. More often than not, total consideration will equate to the stated value on the contract taking into consideration any period or term over which services are to be provided, if applicable. However, we could have contracts in which variable consideration is present. It is common for our contracts which include wireless services to contain customer penalties if rental pagers are not returned and fees for usage of services in excess of the contractually allotted amount for a given period. It is also common for our contracts that include professional services to include travel related costs. These are costs which we incur in the normal course of delivering professional services and are generally billable to the customer based on our incurred expenses. These elements of variable consideration are fully constrained when an agreement is initially executed and are generally not considered estimable until the penalties, fees or costs have been incurred or are otherwise known. We include estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Estimating variable consideration requires significant judgment and our assessment includes all relevant information that is reasonably available to us including historical, current and forecasted information. We have elected to exclude from revenue, all amounts collected on behalf of third parties, and therefore, items such as sales and use tax are excluded from our calculation of the total transaction price. If a contract is separated into more than one performance obligation we allocate the total transaction price to each performance obligation proportionately based on the estimated relative SSPs of the promised goods or services underlying each performance obligation. We rarely sell goods or services with readily observable standalone sales, however, if we do, the observable standalone sales are used to determine the SSP. In most cases, we must estimate the relative SSP which requires significant judgment and estimates. In instances where SSP is not directly observable we determine the SSP using information that may include contractually stated prices, market conditions, costs, renewal contracts, list prices and other observable inputs. A discount is present if the total transaction price is less than the sum of the estimated SSPs of the goods or services promised in the contract. Discounts are generally allocated proportionately based on the relative SSP of the identified performance obligations for a given contract. Our wireless, professional and maintenance services are generally recognized over time due to a customer's simultaneous receipt and consumption of the benefit as we perform the work. As we transfer control over time, we recognize revenue based on the extent of progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires significant judgment and is based on the nature of the products or services to be provided. Generally, we use the time-elapsed measure of progress for performance obligations which include wireless or maintenance services. We believe this method best depicts the simultaneous transfer and consumption of the benefit based on our performance as these services are generally considered standby services. For professional services, we leverage an input methodology based on the number of hours worked on a project versus the total expected hours necessary to complete the project. Revenues are recognized proportionally as hours are incurred. This is a significant area of judgment as it requires an estimate to complete (“ETC”) for each contract. Our initial ETC is primarily based on prior experience also taking into consideration any specific facts and circumstances for a given contract. As projects progress, the ETC is periodically updated and reviewed to ensure the timing of revenue recognition is appropriate. The creation, maintenance and review of a projects ETC requires significant judgment to determine an appropriate number of hours over which the remaining project is expected to be completed. Our software licenses and hardware are generally recognized at a point in time when we have transferred control to the customer. For software licenses, revenue is not recognized until the related license(s) has been made available to the customer and the customer can begin to benefit from its right to use the license(s). Our software licenses represent a right to use Spok’s Intellectual Property (“IP”) as it exists at a point in time at which the license is granted. Many of our software licenses have significant standalone functionality due to their ability to process a transaction or perform a function or task and we do not need to maintain those products, once provided to the customer, for value to exist. While the functionality of IP that we license may substantively change during the license period, customers are not contractually or practically required to update their license as a result of those changes. Assessing when transfer of control has occurred requires significant judgment. In most contracts transfer of control for software licenses occurs in a short period of time after a contract has been executed and licenses are made electronically available. Contracts may be modified to account for changes in a project's scope or other customer requirements. Most of our contract modifications are for goods or services that are distinct from the existing contract or may or may not be distinct but are for services which relate to a series of performance obligations. In these instances, the contract modification would either be recognized as an entirely new and separate contract or the modification would be treated as if it were a termination of the existing contract and the creation of a new contract including all untransferred goods and services under the previous contract. Revenue would be recognized on a prospective basis and a cumulative catch-up would not be recognized. Incremental costs of obtaining a contract and costs to fulfill a contract Commissions Expense - Our incremental costs primarily relate to sales commissions. We capitalize commissions and proportionally recognize the related expense to revenue as it is recognized on the underlying performance obligations. Some of these costs may relate to specific future anticipated contracts, specifically future maintenance renewals, which we do not pay commensurate sales commissions on. We amortize commission costs proportionally with revenue, thus it is necessary for us to estimate future revenues when there are future anticipated contracts. We estimate future revenues based on anticipated renewal amounts over an expected useful life (e.g. the period over which we believe the initial sales commissions relate to future anticipated contracts). The expected useful life is based on a review of our product life cycles, customer upgrade patterns and the rate at which customers renew maintenance. Commissions expenses are classified as Selling and Marketing on the Condensed Consolidated Statement of Operations. Shipping and Handling Costs - We incur shipping and handling costs to send and receive messaging devices and other equipment to/from our customers. Amounts billed to customers related to shipping and handling are classified as revenue and the Company’s shipping and handling costs are classified as cost of revenue on the Condensed Consolidated Statement of Operations. Costs and revenues are expensed and recognized as incurred, respectively. Travel and Other Project Costs - We incur travel and other project-related costs as we deliver professional services to customers. Amounts billed to customers related to travel and other project costs are classified as software revenue and the Company’s travel and other project costs are classified as cost of revenue on the Condensed Consolidated Statement of Operations. Generally, these costs relate to performance obligations which are satisfied or partially satisfied, and therefore, costs are expensed and revenues are recognized as incurred, respectively.