Spok (SPOK) 10-K 18 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 12, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-32358
Entity Registrant Name	SPOK HOLDINGS, INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1694797
Entity Address, Address Line One	6850 Versar Center, Suite 420
Entity Address, City or Town	Springfield
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22151-4148
City Area Code	800
Local Phone Number	611-8488
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	SPOK
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 178
Entity Common Stock, Shares Outstanding (shares)		19,369,436
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement for the 2021 Annual Meeting of Stockholders of the registrant, which will be filed with the Securities and Exchange Commission pursuant to Regulation 14A no later than April 30, 2021, are incorporated by reference into Part III of this Report.
Entity Central Index Key	0001289945
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Security Exchange Name	NASDAQ

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 48,729	$ 47,361
Short-term investments	29,995	29,899
Accounts receivable, net	29,934	30,174
Prepaid expenses	8,958	7,517
Other current assets	1,269	2,714
Total current assets	118,885	117,665
Non-current assets:
Property and equipment, net	7,815	8,000
Operating lease right-of-use assets	14,016	16,317
Capitalized software development, net	10,179	0
Goodwill	99,175	124,182
Intangible assets, net	417	2,917
Deferred income tax assets, net	25,826	48,983
Other non-current assets	978	1,808
Total non-current assets	158,406	202,207
TOTAL ASSETS	277,291	319,872
Current liabilities:
Accounts payable	6,685	3,615
Accrued compensation and benefits	14,103	11,680
Deferred revenue	27,686	25,944
Operating lease liabilities	5,264	5,437
Other current liabilities	3,702	4,507
Total current liabilities	57,440	51,183
Non-current liabilities:
Asset retirement obligations	7,289	6,061
Operating lease liabilities	9,456	11,575
Other non-current liabilities	2,493	959
Total non-current liabilities	19,238	18,595
TOTAL LIABILITIES	76,678	69,778
COMMITMENTS AND CONTINGENCIES (Note 10)
STOCKHOLDERS’ EQUITY:
Preferred stock—$0.0001 par value; 25,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock—$0.0001 par value; 75,000,000 shares authorized; 19,384,192 and 19,071,614 shares issued and outstanding as of December 31, 2020 and December 31, 2019, respectively.	2	2
Additional paid-in capital	91,780	86,874
Accumulated other comprehensive loss	(1,452)	(1,601)
Retained earnings	110,283	164,819
TOTAL STOCKHOLDERS’ EQUITY	200,613	250,094
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 277,291	$ 319,872

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (shares)	25,000,000	25,000,000
Preferred stock, shares issued (shares)	0	0
Preferred stock, shares outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (shares)	75,000,000	75,000,000
Common stock, shares issued (shares)	19,384,192	19,071,614
Common stock, shares outstanding (shares)	19,384,192	19,071,614

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 148,180	$ 160,289	$ 169,474
Operating expenses:
Cost of revenue (exclusive of items shown separately below)	28,542	30,072	32,408
Research and development	15,828	27,543	24,464
Technology operations	29,843	31,428	31,356
Selling and marketing	19,467	23,170	24,553
General and administrative	43,102	45,787	49,097
Depreciation, amortization and accretion	9,056	9,249	10,769
Goodwill impairment	25,007	8,849	0
Total operating expenses	170,845	176,098	172,647
Operating loss	(22,665)	(15,809)	(3,173)
Interest income	687	1,651	1,638
Other income (expense)	208	735	(650)
Loss before income taxes	(21,770)	(13,423)	(2,185)
(Provision for) benefit from income taxes	(22,455)	2,658	706
Net loss	$ (44,225)	$ (10,765)	$ (1,479)
Basic and diluted net loss per common share (usd per share)	$ (2.32)	$ (0.56)	$ (0.08)
Basic and diluted weighted average common shares outstanding (shares)	19,028,918	19,089,402	19,667,891
Cash dividends declared per common share (usd per share)	$ 0.50	$ 0.50	$ 0.50
Wireless
Revenue:
Total revenue	$ 83,593	$ 88,167	$ 94,277
Software
Revenue:
Total revenue	$ 64,587	$ 72,122	$ 75,197

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (44,225)	$ (10,765)	$ (1,479)
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	149	(300)	(49)
Other comprehensive income (loss)	149	(300)	(49)
Comprehensive loss	$ (44,076)	$ (11,065)	$ (1,528)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Adjustment to beginning balance due to adoption of ASC 606 and related tax impact	Common Stock	Additional Paid-In Capital and Accumulated Other Comprehensive Loss	Additional Paid-In Capital and Accumulated Other Comprehensive LossAdjustment to beginning balance due to adoption of ASC 606 and related tax impact	Retained Earnings	Retained EarningsAdjustment to beginning balance due to adoption of ASC 606 and related tax impact	2012 Equity PlanCommon Stock
Beginning balance (shares) at Dec. 31, 2017			20,135,514
Beginning balance at Dec. 31, 2017	$ 290,529	$ 4,944	$ 2	$ 98,731	$ (166)	$ 191,796	$ 5,110
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (1,479)
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201409Member
Issuance of common stock under the Employee Stock Purchase Plan (shares)			20,120
Issuance of common stock under the Employee Stock Purchase Plan	$ 247			247
Issuance of restricted common stock under the Equity Plan (shares)			24,989					199,991
Purchase of common stock for tax withholding (shares)			(62,432)
Purchase of common stock for tax withholding	(976)			(976)
Amortization of stock-based compensation	4,954			4,954
Cash dividends declared	(10,133)					(10,133)
Common stock repurchase program (shares)			(929,116)
Common stock repurchase program including commissions	(13,483)			(13,483)
Cumulative translation adjustment	(49)			(49)
Ending balance (shares) at Dec. 31, 2018			19,389,066
Ending balance at Dec. 31, 2018	274,554		$ 2	89,258		185,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (10,765)
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Issuance of common stock under the Employee Stock Purchase Plan (shares)			23,299
Issuance of common stock under the Employee Stock Purchase Plan	$ 264			264
Issuance of restricted common stock under the Equity Plan (shares)			32,145					233,507
Issuance of restricted stock under the 2012 Equity Plan	154					154
Purchase of common stock for tax withholding (shares)			(74,049)
Purchase of common stock for tax withholding	(1,017)			(1,017)
Amortization of stock-based compensation	3,643			3,643
Cash dividends declared	(9,864)					(9,864)
Common stock repurchase program (shares)			(532,354)
Common stock repurchase program including commissions	(6,575)			(6,575)
Cumulative translation adjustment	(300)			(300)
Ending balance (shares) at Dec. 31, 2019			19,071,614
Ending balance at Dec. 31, 2019	250,094	$ (365)	$ 2	85,273		164,819	$ (365)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(44,225)
Issuance of common stock under the Employee Stock Purchase Plan (shares)			35,661
Issuance of common stock under the Employee Stock Purchase Plan	300			300
Issuance of restricted common stock under the Equity Plan (shares)			74,027					282,871
Purchase of common stock for tax withholding (shares)			(79,981)
Purchase of common stock for tax withholding	(902)			(902)
Amortization of stock-based compensation	5,508			5,508
Cash dividends declared	(9,946)					(9,946)
Cumulative translation adjustment	149			149
Ending balance (shares) at Dec. 31, 2020			19,384,192
Ending balance at Dec. 31, 2020	$ 200,613		$ 2	$ 90,328		$ 110,283

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (44,225)	$ (10,765)	$ (1,479)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, amortization and accretion	9,056	9,249	10,769
Goodwill impairment	25,007	8,849	0
Valuation allowance	22,108	0	0
Deferred income tax expense (benefit)	438	(3,253)	(1,692)
Stock-based compensation	5,508	3,643	4,954
Provisions for doubtful accounts, service credits, adjustments of non-cash transaction taxes and other	1,212	694	1,922
Changes in assets and liabilities:
Accounts receivable	(1,588)	964	(915)
Prepaid expenses and other assets	1,445	2,913	(646)
Accounts payable, accrued liabilities and other	4,027	(643)	(1,732)
Deferred revenue	3,175	42	(866)
Net cash provided by operating activities	26,163	11,693	10,315
Cash flows from investing activities:
Purchases of property and equipment	(3,455)	(4,837)	(5,915)
Capitalized software development	(11,252)	0	0
Purchase of short-term investments	(59,864)	(59,385)	(3,911)
Maturity of short-term investments	60,000	34,000	4,000
Net cash used in investing activities	(14,571)	(30,222)	(5,826)
Cash flows from financing activities:
Cash distributions to stockholders	(9,771)	(9,819)	(10,064)
Purchase of common stock (including commissions)	0	(6,575)	(13,483)
Proceeds from issuance of common stock under the Employee Stock Purchase Plan	301	258	247
Purchase of common stock for tax withholding on vested equity awards	(903)	(1,017)	(976)
Net cash used in financing activities	(10,373)	(17,153)	(24,276)
Effect of exchange rate on cash	149	(300)	(49)
Net increase (decrease) in cash and cash equivalents	1,368	(35,982)	(19,836)
Cash and cash equivalents, beginning of period	47,361	83,343	103,179
Cash and cash equivalents, end of period	48,729	47,361	83,343
Supplemental disclosure:
Income taxes paid	$ 1	$ 901	$ 1,061

Organization and Significant Ac

Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES	ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Spok, Inc., a wholly owned subsidiary of Spok Holdings, Inc. (NASDAQ: SPOK) ("Spok," the "Company," "we," "us" and "our") is proud to be the global leader in healthcare communications. We deliver clinical information to care teams when and where it matters most to improve patient outcomes. Top hospitals rely on Spok products and services to enhance workflows for clinicians, support administrative compliance, and provide a better experience for patients. We offer a focused suite of unified clinical communication and collaboration solutions that include call center operations, clinical alerting and notifications, one-way and advanced two-way wireless messaging services, mobile communications and public safety solutions. We provide one-way and advanced two-way wireless messaging services, including information services, throughout the United States. These services are offered on a local, regional and nationwide basis, employing digital networks. One-way messaging consists of numeric and alphanumeric messaging services. Numeric messaging services enable subscribers to receive messages that are composed entirely of numbers, such as a phone number, while alphanumeric messages may include numbers and letters, which enable subscribers to receive text messages. Two-way messaging services enable subscribers to send and receive messages to and from other wireless messaging devices, including pagers, personal digital assistants and personal computers. We also offer voice mail, personalized greetings, message storage and retrieval, and equipment loss and/or maintenance protection to both one-way and two-way messaging subscribers. These services are commonly referred to as wireless messaging and information services. We also develop, sell and support enterprise-wide systems for hospitals and other organizations needing to automate, centralize and standardize clinical communications. These solutions are used for contact centers, clinical alerting and notification, mobile communications and messaging and for public safety notifications. These areas of market focus compliment the market focus of our wireless services outlined above. Basis of Presentation The accompanying 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 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 Consolidated Financial Statements include all adjustments and accruals that are necessary for the presentation of the results of all periods reported herein and all such adjustments are of a normal, recurring nature, with the exception of our adoption of ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, often referred to as Current Expected Credit Losses ("CECL"). For additional details refer to Note 2, "Recent Accounting Standards." Amounts shown on the consolidated statements of operations within the operating expense categories of cost of revenue; research and development; technology operations; selling and marketing; and general and administrative are recorded exclusive of depreciation, amortization and accretion. These items are shown separately on the Consolidated Statements of Operations within operating expenses to the extent that they are considered material for the periods presented. Certain immaterial prior period amounts in the consolidated financial statements have been reclassified to conform to the current period's presentation. These reclassifications had no effect on the reported results of operations or the statement of financial position. Use of Estimates The preparation of these 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 ongoing 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, depreciation expense, asset retirement obligations, 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 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 the product is delivered, when services begin and, to a lesser extent, when services are completed. For Software as a Service ("SaaS") contracts, the subscription and premium support services are generally billed annually in advance while professional services are billed at various milestones which reflect work 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 Consolidated Balance Sheets, primarily due to the receipt of payment in advance of the product or services we provide. Amounts billed and due from our customers are classified as accounts receivable on the Consolidated Balance Sheets. 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 Consolidated Financial Statements. 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 would not adjust the total consideration for the effects of a significant financing component if we anticipate, at contract inception, that the period between when we transfer a promised good or service to a customer and when the customer pays for that good or service will be one year or less. We account for a contract when: (1) both parties have approved the contract through mutually signed agreements or 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. Wireless service contracts are generally considered to be a single promise and therefore accounted for as a single performance obligation. Contracts which include goods or services related to our software solutions and subscriptions 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. Material performance obligations related to the sale of our SaaS platform include a SaaS subscription, professional services, and signature support services. 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 that 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 standalone selling price ("SSP") of the promised goods or services underlying each performance obligation. We rarely sell goods or services as 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, maintenance, and subscription 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 that include wireless, maintenance, or subscription 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 at completion ("EAC") for each contract. Our initial EAC is primarily based on prior experience also taking into consideration any specific facts and circumstances for a given contract. As projects progress, the EAC is periodically updated and reviewed to ensure the timing of revenue recognition is appropriate. The creation, maintenance and review of a project's EAC 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. 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. 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 undelivered 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 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. Commission expense was $4.3 million, $5.0 million and $6.2 million for the years ended December 31, 2020, 2019 and 2018, respectively. Commission expense is classified within the selling and marketing operating expenses category. Leases Operating lease right-of-use ("ROU") assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. We have made an accounting policy election not to apply the recognition requirements of ASC 842, "Leases," to short-term leases. Those leases which have a term of less than 12 months will have lease payments recognized, in our Consolidated Statements of Operations, on a straight-line basis over the lease term. An optional renewal or termination is not recognized as part of the lease term unless we determine that it is reasonably certain that we will exercise that option. The term reasonably certain is a high threshold for which pervasive evidence generally does not exist, and therefore, optional renewal periods are generally excluded from our ROU assets and lease liabilities until they have been exercised. Lease expense is recognized on a straight-line basis over the lease term. As most of our leases do not provide an implicit rate, we use an estimated incremental borrowing rate in determining the present value of lease payments. The Company uses a portfolio approach when determining the discount rate applied to its leases. Significant judgment is necessary when determining a discount rate because we must estimate the discount rate based on a number of factors and observable inputs including current market conditions, market yields, government bond rates, credit risk, and other factors as necessary. The Company must also exercise significant judgment when determining whether an option to renew or terminate a lease should be included in the lease term. This judgment includes an assessment of all relevant economic factors such as costs relating to the termination or extension of a lease, importance of the underlying asset to the Company’s operations, and the terms and conditions of the optional periods in relation to current market rates. Where we have lease agreements which contain lease and non-lease components, we have elected to make use of the practical expedient to account for each separate lease component and associated non-lease component as a single lease component. Impairment of Long-Lived Assets, Intangible Assets Subject to Amortization and Goodwill We are required to evaluate the carrying value of our long-lived assets, amortizable intangible assets and goodwill. Amortizable intangible assets include customer-related intangibles that resulted from previous acquisitions. Such intangibles are amortized over periods up to ten years. Quarterly, we assess whether circumstances exist which suggest that the carrying value of long-lived and amortizable intangible assets may not be recoverable. When applicable, we assess the recoverability of the carrying value of our long-lived assets and certain amortizable intangible assets based on estimated undiscounted cash flows generated from such assets. In assessing the recoverability of these assets, we forecast estimated enterprise-level cash flows based on various operating assumptions such as revenue forecasted by product line and in-process research and development cost. If the forecast of undiscounted cash flows does not exceed the carrying value of the long-lived and amortizable intangible assets, we record an impairment charge to the extent the carrying value exceeded the fair value of such assets. Goodwill is not amortized but is evaluated for impairment at least annually, or when events or circumstances suggest a potential impairment has occurred. We generally perform this annual impairment test in the fourth quarter of the fiscal year. We evaluate goodwill for impairment between annual tests if indicators of impairment exist. The impairment test involves comparing the fair value of the reporting unit with its carrying value. An impairment charge is recognized for the amount that the carrying value exceeds the reporting unit's fair value. For purposes of the goodwill impairment evaluation, the Company as a whole is considered the reporting unit. The fair value of the reporting unit is estimated under a market-based approach using the fair value of the Company's common stock. The estimated fair value requires significant judgments, including timing and appropriateness of the price of common stock used (e.g. point-in-time application, simple moving average, exponential moving average), as well as application of an estimated control premium. The estimated control premium is based on a review of current and past market information published by a third-party resource, assessment of the Company's future projected discounted cash flows and other relevant information if available. Based on our assessment during the fourth quarter of 2020, the estimated fair value exceeded the carrying value of the reporting unit and, therefore, an impairment existed. For additional details refer to Note 6, "Goodwill and Intangible Assets, Net." We did not record any impairment of long-lived assets or definite-lived intangible assets for the years ended December 31, 2020, 2019 and 2018. Accounts Receivable Allowances Our two most significant allowance accounts are: an allowance for doubtful accounts and an allowance for service credits. Provisions for these allowances are recorded on a monthly basis and are included as a component of general and administrative expenses, respectively. Estimates are used in determining the allowance for doubtful accounts and are based on historical collection experience and current and forecasted trends, as well as known specific collection risks. In determining these estimates, we review historical write-offs, including comparisons of write-offs to provisions for doubtful accounts. We compare the ratio of the allowance to gross receivables to historical levels, and monitor amounts collected and related statistics. We write off receivables when they are deemed uncollectible. While write-offs of customer accounts have historically been within our expectations and the provisions established, we cannot guarantee that the future write-off experience will be consistent with historical experience, which could result in material differences when compared to the allowance for doubtful accounts and related provisions. From time to time, we grant service credits for customer retention purposes or when there is an adjustment in the scope of work. The allowance for service credits related provisions are based on historical credit percentages, current credit and aging trends, historical actual payment trends and actual credit experience. We analyze our past credit experience over several time frames. Using this analysis along with current operational data, including existing experience of credits issued and the time frames in which credits are issued, we establish an appropriate allowance for service credits. This allowance also reduces accounts receivable for lost and non-returned pagers to the expected realizable amounts and for free wireless services. While credits issued have been within our expectations and the provisions established, we cannot guarantee that future credit experience will be consistent with historical experience, which could result in material differences when compared to the allowance for service credits and maintenance-related provisions. Inventory Inventories are stated at the lower of cost or net realizable value. Cost is computed using a weighted average cost approach which averages the prices at which goods are purchased from vendors. We evaluate our ending inventories for shrinkage and estimated obsolescence. Any shrinkage identified is written off to cost of goods sold in the period in which the shrinkage is identified. Further, we assess the impact of changing technology on our inventories and we write off inventories that are considered obsolete in the period in which the analysis takes place. Inventory consists primarily of finished goods. We do not account for inventory as work-in-process or raw materials as any such inventory would be immaterial to the consolidated financial statements. Property and Equipment Property and equipment are reported at cost and are depreciated using the straight-line method based on estimated useful lives which range from one Transmitter assets are grouped into tranches based on our transmitter decommissioning forecast and are depreciated using the group life method on a straight-line basis. Depreciation expense is determined by the expected useful life of each tranche of the underlying transmitter assets. The expected useful life is based on our forecasted usage of those assets and their retirement over time and aligns the useful lives of these transmitter assets with their planned removal from service. Disposals are charged against accumulated depreciation with no gain or loss recognized. This rational and systematic method matches the underlying usage of these assets to the underlying revenue that is generated from these assets. Depreciation expense for these assets is subject to change based upon revisions in the timing of transmitter deconstruction resulting from our long-range planning and network rationalization process. Asset Retirement Obligations We recognize liabilities and corresponding assets for future obligations associated with the retirement of assets. We have paging equipment assets, principally transmitters, which are located at leased locations. The underlying leases generally require the removal of equipment at the end of the lease term; therefore, a future obligation exists. Asset retirement costs are reflected in paging equipment assets with depreciation expense recognized over the estimated lives, which range between one The recognition of an asset retirement obligation requires that management make numerous assumptions regarding such factors as the cost and timing of deconstruction; the credit-adjusted risk-free rate to be used; inflation rates; and future advances in technology. The fair value estimate of contractor fees to remove each asset is assumed to escalate by 2% each year through the terminal date. The total estimated liability is based on the estimated future value of those costs and the timing of deconstruction. We believe these estimates are reasonable at the present time, but we can give no assurance that changes in technology, our financial condition, the economy or other factors would not result in higher or lower asset retirement obligations. Any variations from our estimates would generally result in a change in the assets and liabilities in equal amounts, and operating results would differ in the future by any difference in depreciation expense and accretion expense (see Note 5, "Consolidated Financial Statement Components", and Note 7, "Asset Retirement Obligations" for additional details). Income Taxes We file a consolidated U.S. federal income tax return and income tax returns in state, local and foreign jurisdictions as required. The provision for current income taxes is calculated and accrued on income and expenses expected to be included in current year U.S. and foreign income tax returns. The provision for current income taxes may also include interest, penalties and an estimated amount reflecting uncertain tax positions. Deferred income tax assets and liabilities are calculated based on temporary differences between the financial statement values and the tax bases of assets and liabilities including net operating loss and tax credit carryforwards at the enacted tax rates expected to apply to taxable income when taxes are actually paid or recovered. Changes in deferred income tax assets and liabilities are included as a component of deferred income tax expense. Deferred income tax assets represent amounts available to reduce future income taxes payable. We assess the recoverability of our deferred income tax assets, which represent the tax benefits of future tax deductions, based on available positive and negative evidence and by considering the adequacy of future taxable income from all sources, including prudent and feasible tax planning strategies. This assessment is required to determine whether based on all available evidence, it is "more likely than not" (meaning a probability of greater than 50%) that all or some portion of the deferred income tax assets will be realized in future periods. We provide a valuation allowance when we consider it "more likely than not" that a deferred income tax asset will not be fully recovered. The assessment of our deferred income tax assets requires significant judgment. Assets and liabilities are established for uncertain tax positions taken or positions expected to be taken in income tax returns when such positions fail to meet the "more likely than not" threshold based on the technical merits of the positions. We assess whether previously unrecognized tax benefits may be recognized when the tax position is (1) more likely than not of being sustained based on its technical merits, (2) effectively settled through examination, negotiation or litigation, or (3) settled through actual expiration of the relevant tax statutes. The assessment of an uncertain tax position requires significant judgment. We had no uncertain tax positions for the periods ended December 31, 2020 and 2019 (see Note 9, "Income Taxes," for additional details). Research and Development In accordance with ASC 985-20, Software to be Sold, Leased, or Marketed, certain software development costs are charged to operations and expensed as incurred until technological feasibility has been established. Material costs incurred after technological feasibility is established and before the product is ready for general release are capitalized and amortized on a straight-line basis over the estimated remaining economic life of the product or the ratio of current revenues to total projected product revenues, whichever is greater. To date, the time between technological feasibility and general release to the public has been extremely short and consequently expenses available for capitalization have been immaterial. Accordingly, all research and developments costs incurred to date, accounted for in accordance with ASC 985-20, have been expensed as incurred. In accordance with ASC 350-40, Internal-Use Software, certain software development costs are capitalized while in the application development stage related to software developed for internal use or software sold in a Software as a Service ("SaaS") arrangement. This includes certain development costs for Spok Go which qualified for capitalization beginning in the first quarter of 2020. All other costs incurred during the preliminary project stage or the post-implementation stage, are expensed as incurred. Significant judgment is required when assessing costs and determining whether they fall within the preliminary project, application development, or post-implementation stage that determines whether the associated costs are expensed as incurred or capitalized. Capitalized software development is amortized on a straight-line basis over the estimated useful life of the asset, typically three years, beginning when those development efforts have been placed into service (e.g., generally once made commercially available). Determining the estimated useful life requires significant judgment as we consider factors such as the rapid and continuous developments in software technology, obsolescence and anticipated life of the service offering before enhancements are necessary. In a SaaS environment, customer needs are rapidly evolving and a shorter useful life is generally expected. 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. These costs are expensed as incurred. Advertising Expenses Advertising costs are charged to operations when incurred. Advertising costs are classified as selling and marketing expenses. Advertising expenses were $1.3 million , $1.7 million and $2.4 million for the years ended December 31, 2020, 2019, and 2018, respectively. Stock-Based Compensation We account for share-based payments to employees, including restricted stock uni

Recent Accounting Standards

Recent Accounting Standards	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
RECENT ACCOUNTING STANDARDS	RECENT ACCOUNTING STANDARDSIn June 2016, the Financial Accounting Standards Board issued ASU No. 2016-13, or CECL. CECL requires early recognition of credit losses on financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This guidance is effective for fiscal years beginning after December 15, 2019. On January 1, 2020, we adopted ASU No. 2016-13 which resulted in an immaterial adjustment to the beginning balance of retained earnings and an increase to allowance for doubtful accounts.

Revenue, Deferred Revenue and P

Revenue, Deferred Revenue and Prepaid Commissions	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
REVENUE, DEFERRED REVENUE, AND PREPAID COMMISSIONS	REVENUE, DEFERRED REVENUE AND PREPAID COMMISSIONS Revenue Recognition Revenues are recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. The following table presents our revenues disaggregated by revenue type: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Revenue - wireless: Paging revenue $ 79,916 $ 85,067 $ 90,570 Product and other revenue 3,677 3,100 3,707 Total wireless revenue $ 83,593 $ 88,167 $ 94,277 Revenue - software: License $ 5,179 $ 8,950 $ 13,042 Services 17,910 19,189 18,091 Equipment 2,841 3,618 4,995 Subscription 66 — — Operations revenue 25,996 31,757 36,128 Maintenance revenue 38,591 40,365 39,069 Total software revenue $ 64,587 $ 72,122 $ 75,197 Total revenue $ 148,180 $ 160,289 $ 169,474 The Company is currently structured as a single operating (and reportable) segment, a clinical communication and collaboration business. The U.S. was the only country that accounted for more than 10% of the Company’s total revenue for the years ended December 31, 2020, 2019 and 2018. Revenue generated in the U.S. and internationally consisted of the following for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Revenue: United States $ 145,349 $ 154,766 $ 164,558 International 2,831 5,523 4,916 Total revenue $ 148,180 $ 160,289 $ 169,474 Deferred Revenues Our deferred revenues represent payments made to, or due from, customers in advance of our performance. Changes in the balance of total deferred revenue during the twelve months ended December 31, 2020, are as follows: (Dollars in thousands) December 31, 2019 Additions Revenue Recognized December 31, 2020 Deferred Revenue $ 26,621 $ 67,769 $ (64,594) $ 29,796 During the twelve months ended December 31, 2020, the Company recognized $24.7 million of revenue related to amounts deferred as of December 31, 2019. Prepaid Commissions Our prepaid commissions represent payments made to employees in advance of our performance on the related underlying contracts. These costs have been incurred directly in relation to obtaining a contract. As such, these costs are amortized over the estimated period of benefit. Changes in the balance of total prepaid commissions during the year ended December 31, 2020, are as follows: (Dollars in thousands) December 31, 2019 Additions Commissions Recognized December 31, 2020 Prepaid Commissions $ 2,431 $ 4,160 (4,301) $ 2,290 Prepaid commissions are included within prepaid expenses in the Consolidated Balance Sheets and commissions expense is included within Selling and marketing on the Consolidated Statements of Operations. Remaining Performance Obligations

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
LEASES	LEASES We have operating lease arrangements for corporate offices, cellular towers, storage units and small building spaces. The building space is used to house infrastructure, such as transmitters, antennae and other various equipment for the Company’s wireless paging services. For leases with a term of 12 months or less, renewal terms are generally of an evergreen nature (either month-to-month or year-to-year). For leases with a term greater than 12 months, renewal terms are generally explicit and provide for one to five optional renewals consistent with the initial term. Many of our leases, with the exception of those for our corporate offices, include options to terminate the lease within one year. Variable lease payments, residual value guarantees or purchase options are not generally present in these leases. Lease costs are included in Technology Operations and General and Administrative expenses on the Consolidated Statements of Operations. The following table presents lease costs disaggregated by type: For the Year Ended December 31, (Dollars in thousands) 2020 2019 Operating lease cost $ 5,797 $ 5,823 Short-term lease cost 7,991 8,281 Short-term lease cost - related party (1) 3,518 3,589 Total lease cost $ 17,306 $ 17,693 Supplemental Disclosure: Cash paid for amounts included in the measurement of lease liabilities - operating leases $ 5,685 $ 5,678 Weighted-average remaining lease term - operating leases (in years) 5.06 5.60 Weighted-average discount rate - operating leases 5.17% 5.45% (1) A former member of our Board of Directors, who departed our Board during the third quarter of 2020, also serves as a director for an entity that leases transmission tower sites to the Company. Refer to Note 12, "Related Parties" for additional details. We intend to relocate our corporate headquarters during the first half of 2021 to office space located in Alexandria, Virginia, consisting of approximately 26,000 square feet of space under a lease that will expire on September 30, 2026. We expect to record approximately $4.4 million in a right-of-use asset and corresponding operating lease liability for this lease at such time that we obtain control of the property. Maturities of lease liabilities as of December 31, 2020, were as follows: (Dollars in thousands) For the Year Ended December 31, 2021 $ 5,273 2022 3,539 2023 2,395 2024 1,672 2025 1,050 Thereafter 2,816 Total future lease payments 16,745 Imputed interest (2,025) Total $ 14,720

Consolidated Financial Statemen

Consolidated Financial Statements' Components	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
CONSOLIDATED FINANCIAL STATEMENTS' COMPONENTS	CONSOLIDATED FINANCIAL STATEMENTS' COMPONENTS Depreciation, Amortization and Accretion Depreciation, amortization and accretion consisted of the following for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Depreciation Leasehold improvements $ 57 $ 63 $ 232 Asset retirement costs (643) (766) (300) Paging and computer equipment 5,291 6,526 7,397 Furniture, fixtures and vehicles 307 374 398 Total depreciation 5,012 6,197 7,727 Amortization Intangible assets 2,500 2,500 2,500 Capitalized software development costs 1,073 — — Total amortization 3,573 2,500 2,500 Accretion 471 552 542 Total depreciation, amortization and accretion expense $ 9,056 $ 9,249 $ 10,769 Accounts Receivable, net Accounts receivable was recorded net of an allowance of $1.7 million and $1.3 million for the years ended December 31, 2020, and 2019, respectively. Accounts receivable, net includes $7.0 million and $6.4 million of unbilled receivables for the years ended December 31, 2020, and 2019, respectively. Unbilled receivables are defined as the Company's right to consideration in exchange for goods or services that we have transferred to the customer but have not yet billed for, generally as a result of contractual billing terms. Property and Equipment, net Property and equipment, net consisted of the following for the periods stated: Useful Life For the Year Ended December 31, (Dollars in thousands) 2020 2019 Leasehold improvements lease term $ 3,628 $ 3,620 Asset retirement costs 1-5 3,717 1,922 Paging and computer equipment 1-5 92,608 96,562 Furniture, fixtures and vehicles 3-5 3,517 3,716 Total property and equipment 103,470 105,820 Accumulated depreciation (95,655) (97,820) Total property and equipment, net $ 7,815 $ 8,000 For purposes of assessing our asset retirement costs, we completed a review of the estimated useful life of our transmitter assets during the fourth quarter of 2020 (that are part of paging and computer equipment). This review was based on the results of our long-range planning and network rationalization process and indicated that the expected useful life of the last tranche of the transmitter assets was no longer appropriate. As a result of that review, the expected useful life of the final tranche of transmitter assets was extended from 2024 to 2025. This change resulted in a revision of the expected future depreciation expense for the transmitter assets and an immaterial impact to the consolidated financial statements beginning in 2021. We believe these estimates remain reasonable at the present time, but we can give no assurance that changes in technology, customer usage patterns, our financial condition, the economy or other factors would not result in changes to our transmitter decommissioning plans. Any further variations from our estimates could result in a change in the expected useful lives of the underlying transmitter assets and operating results could differ in the future by any difference in depreciation expense. The extension of the depreciable life was accounted for as a change in accounting estimate. Capitalized Software Development Capitalized software development is amortized on a straight-line basis over the estimated useful life of the asset, typically three years. Capitalized software development costs were $11.3 million for the year ended December 31, 2020, and no capitalized costs were recorded for the year ended December 31, 2019, respectively. Amortization expense with respect to software development costs was $1.1 million for the year ended December 31, 2020, and there was no amortization expense for the year ended December 31, 2019.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS, NET	GOODWILL AND INTANGIBLE ASSETS, NET Goodwill For purposes of the goodwill impairment assessment, the Company as a whole is considered the reporting unit. The fair value of the reporting unit is estimated under a market-based approach using the fair value of the Company's common stock. The estimated fair value requires significant judgments, including timing and appropriateness of the price of common stock used (e.g., point-in-time application, simple moving average, exponential moving average), as well as application of an estimated control premium. There are a number of judgmental factors that are incorporated into our assessment to establish an estimated control premium, including the review of current and past market information published by a third-party resource, assessment of the Company's future projected discounted cash flows and other relevant information if available. While a formal impairment assessment is performed annually, the Company monitors its business environment for potential triggering events on a quarterly basis. During the quarter ended March 31, 2020, we determined, based on a qualitative assessment, that COVID-19 created a triggering event that required further assessment. As such, we performed a quantitative assessment, using data as of March 31, 2020. Based on that assessment, the estimated fair value of the reporting unit exceeded the carrying value of the Company, which indicated an impairment did not exist as of the interim balance sheet date. During the quarter ended December 31, 2020, we performed our annual assessment of goodwill. Based on our assessment, using data as of October 31, 2020, the carrying value of the reporting unit exceeded the estimated fair value of the Company, which indicated an impairment existed. There is potential for further impairment charges in future periods based on these ongoing assessments. The change in goodwill for the year ended December 31, 2020, was as follows: (Dollars in thousands) Change in Goodwill Goodwill at January 1, 2019 $ 133,031 Impairment $ (8,849) Goodwill at January 1, 2020 $ 124,182 Impairment (25,007) Goodwill at December 31, 2020 $ 99,175 Intangible Assets Amortizable intangible assets at December 31, 2020 and 2019 related primarily to customer relationships. Such intangible assets are amortized over a period of ten years. We did not record an impairment of our intangible assets during the years ended December 31, 2020, 2019 and 2018. The remaining amortization of $0.4 million is expected to be incurred in 2021. The net consolidated balance of intangible assets consisted of the following at December 31, 2020, and 2019: As of December 31, 2020 2019 (Dollars in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 25,002 $ (24,585) $ 417 $ 25,002 $ (22,085) $ 2,917

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS	ASSET RETIREMENT OBLIGATIONS The components of the changes in the asset retirement obligation liabilities for the periods stated were as follows: (Dollars in thousands) Short-Term Portion Long-Term Portion Total Balance at January 1, 2019 $ 34 $ 6,513 $ 6,547 Accretion 39 513 552 Amounts paid (177) — (177) Additions — 32 32 Reductions 14 (817) (803) Reclassifications 180 (180) — Balance at December 31, 2019 90 6,061 6,151 Accretion (38) 509 471 Amounts paid (352) — (352) Additions 169 1,185 1,354 Reclassifications 466 (466) — Balance at December 31, 2020 $ 335 $ 7,289 $ 7,624 Increases and reductions other than accretion, reclassification and amounts paid primarily relate to changes in estimates of the underlying liability, specifically related to updates in estimated costs to remove a transmitter and the estimated timing of removal. Estimated removal costs and timing refinements due to ongoing network rationalization activities are expected to accrete to a total liability of $9.3 million. Additional information regarding asset retirement costs and accretion expense can be found in Note 5, "Consolidated Financial Statements' Components."

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY General Our authorized capital stock consists of 75 million shares of common stock, par value $0.0001 per share, and 25 million shares of preferred stock, par value $0.0001 per share. At December 31, 2020, and 2019, we had no stock options outstanding. At December 31, 2020, and 2019, there were 19,384,192 and 19,071,614 shares of common stock outstanding, respectively, and no shares of preferred stock were outstanding. Dividends For each of the three years ending December 31, 2020, 2019 and 2018, our Board of Directors declared cash dividends of $0.50 per share of our outstanding common stock. An immaterial amount of dividends declared were related to unvested RSUs and unvested shares of restricted stock, which are accrued for and paid when the applicable vesting conditions are met. Accrued cash dividends on forfeited RSUs and restricted stock are also forfeited. Cash dividends paid as disclosed in the Consolidated Statements of Cash Flows for the years ended December 31, 2020, 2019 and 2018 included previously declared cash dividends on vested RSUs and on shares of vested restricted stock issued to non-executive members of our Board of Directors. On February 17, 2021, the Board of Directors declared a regular quarterly cash dividend of $0.125 per share of common stock, with a record date of March 16, 2021, and a payment date of March 30, 2021. This cash dividend of approximately $2.4 million is expected to be paid from available cash on hand. Common Stock Repurchase Program On July 31, 2008, our Board of Directors approved a program to repurchase our common stock in the open market. This program has been extended at various times. In August 2018, our Board of Directors authorized the repurchase of up to $10.0 million of our common stock through December 31, 2018, on the open market or in privately negotiated transactions. In November 2018, our Board of Directors extended the repurchase authority through December 31, 2019. The Company fully exhausted the repurchase authority in September 2019. We used available cash on hand and net cash provided by operating activities to fund the common stock repurchase program. This repurchase authority allowed us, at management’s discretion, to selectively repurchase shares of our common stock from time to time in the open market depending upon market price and other factors. Repurchased shares of our common stock were accounted for as a reduction to common stock and additional paid-in-capital in the period in which the repurchase occurred. All repurchased shares of common stock were returned to the status of authorized, but unissued, shares of the Company. The Company did not repurchase any of its common stock during 2020. Common stock repurchased in 2019 and 2018 (excluding commission and the purchase of common stock for tax withholdings) was as follows: (Dollars in thousands, except for shares purchased) 2019 2018 For the Three Months Ended Shares Purchased Amount Shares Purchased Amount March 31, 131,012 $ 1,806 127,792 $ 1,922 June 30, — — 501,782 7,520 September 30, 401,342 4,749 36,542 558 December 31, — — 263,000 3,446 Total 532,354 $ 6,555 929,116 $ 13,446 Net Loss per Common Share Basic net loss per common share is computed on the basis of the weighted average common shares outstanding. Diluted net loss per common share is computed on the basis of the weighted average common shares outstanding plus the effect of all potentially dilutive common shares, including unvested and outstanding equity awards. The components of basic and diluted net loss per common share were as follows for the periods stated: For the Year Ended December 31, (In thousands, except for share and per share amounts) 2020 2019 2018 Numerator: Net loss $ (44,225) $ (10,765) $ (1,479) Denominator: Basic and diluted weighted average outstanding shares of common stock 19,028,918 19,089,402 19,667,891 Basic and diluted net loss per common share $ (2.32) $ (0.56) $ (0.08) For the years ended December 31, 2020, 2019 and 2018, the following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive: For the Year Ended December 31, 2020 2019 2018 Restricted stock units 297,757 189,862 178,279 Share-Based Compensation Plans On March 23, 2012, our Board of Directors adopted the Spok Holdings, Inc. 2012 Equity Incentive Award Plan (the "2012 Equity Plan") that our stockholders subsequently approved on May 16, 2012. A total of 2,194,986 shares of common stock were reserved for issuance under this plan. On April 29, 2020, our Board of Directors adopted the Spok Holdings, Inc. 2020 Equity Incentive Award Plan (the "2020 Equity Plan" and together with the 2012 Equity Plan, the "Equity Plans") that our stockholders subsequently approved on July 28, 2020. As of July 28, 2020, a total of 1,699,950 shares of common stock have been reserved for issuance under the 2020 Equity Plan, and no further grants will be made under the 2012 Equity Plan. However, the 2012 Equity Plan will continue to govern all outstanding awards thereunder. Awards under the 2020 Equity Plan may be in the form of stock options, restricted common stock, RSUs, performance awards, dividend equivalents, stock payment awards, deferred stock, deferred stock units ("DSUs"), stock appreciation rights or other stock or cash-based awards. Restricted stock awards generally vest one year from the date of grant. Related dividends accumulate during the vesting period and are paid at the time of vesting. Contingent RSUs generally vest over a three-year performance period upon successful completion of the performance objectives. Non-contingent RSUs generally vest in thirds, annually, over a three-year period. Dividend equivalent rights generally accompany each RSU award and those rights accumulate and vest along with the underlying RSU. Dividend equivalent rights generally accompany each DSU award and are paid to participants in cash on the Company's applicable dividend payment date whether the DSU is vested or unvested. The dividend equivalent right associated with a DSU continues until delivery of the underlying shares of common stock is made. Payment of the underlying shares of common stock occurs at the earliest of a participant's separation from service, disability, death, or a change in control. Any shares subject to an award under the 2012 Equity Plan that are forfeited or expire will be available for the future grant of awards under the 2020 Equity Plan. As of December 31, 2020, there was an aggregate of 605,606 unvested RSUs and restricted stock outstanding under the 2012 Equity Plan. The following table summarizes the activities under the Equity Plans from January 1, 2018, through December 31, 2020: Activity Total equity securities available at January 1, 2018 1,140,658 Less: RSU and restricted stock awarded to eligible employees, net of forfeitures (236,221) Total equity securities available at December 31, 2018 904,437 Less: RSU and restricted stock awarded to eligible employees, net of forfeitures (257,957) Total equity securities available at December 31, 2019 646,480 Less: RSU, DSU and restricted stock awarded to eligible employees, net of forfeitures (547,166) Plus: Additional shares available for issuance under the 2020 Equity Plan 1,600,000 Total equity securities available at December 31, 2020 1,699,314 The following table details activities with respect to outstanding RSUs, DSUs, and restricted stock under the Equity Plans for the year ended December 31, 2020: Shares Weighted-Average Grant Date Fair Value per Share Unvested at January 1, 2020 419,426 $ 14.00 Granted 603,171 11.94 Vested (329,870) 14.05 Forfeited (56,005) 12.49 Unvested at December 31, 2020 636,722 $ 12.16 Of the 636,722 unvested RSUs and restricted stock outstanding at December 31, 2020, 354,125 RSUs include contingent performance requirements for vesting purposes. At December 31, 2020, there was $4.1 million of unrecognized net compensation cost related to RSUs and restricted stock, which is expected to be recognized over a weighted average period of 1.6 years . During the years ended December 31, 2019 and 2018, the Company granted 388,321 and 343,102 RSUs, respectively, with a weighted-average grant date fair value of $13.27 and $15.65 per share, respectively. The fair value of RSUs that vested during the years ended December 31, 2019 and 2018 were $3.0 million and $2.7 million, respectively, based on the closing price of the Company's common stock of $12.23 and $13.26 at December 31, 2019 and December 31, 2018, respectively. Employee Stock Purchase Plan In 2016, our Board of Directors adopted the ESPP that our stockholders subsequently approved on July 25, 2016. A total of 250,000 shares of common stock were reserved for issuance under this plan. The ESPP allows employees to purchase shares of common stock at a discounted rate, subject to plan limitations. Under the ESPP, eligible participants can voluntarily elect to have contributions withheld from their pay for the duration of an offering period, subject to the ESPP limits. At the end of an offering period, contributions will be used to purchase the Company's common stock at a discount to the market price based on the first or last day of the offering period, whichever is lower. Participants are required to hold common stock for a minimum period of two years from the grant date. Participants will begin earning dividends on shares after the purchase date. Each offering period will generally last for no longer than six months. Once an offering period begins, participants cannot adjust their withholding amount. If a participant chooses to withdraw, any previously withheld funds will be returned to the participant, with no stock purchased, and that participant will be eligible to participate in the ESPP at the next offering period. If the participant terminates employment with the Company during the offering period, all contributions will be returned to the employee and no stock will be purchased. The Company uses the Black-Scholes model to calculate the fair value of each offering period on the offer date. The Black-Scholes model requires the use of estimates for the expected term, the expected volatility of the underlying common stock over the expected term, the risk-free interest rate and the expected dividend payment. For the year ended December 31, 2020, employees purchased 35,661 shares of common stock for a total price of $0.3 million. For the year ended December 31, 2019, employees purchased 23,299 shares of common stock for a total price of $0.3 million. The following table summarizes the activities under the ESPP from January 1, 2018, through December 31, 2020: Activity Total ESPP equity securities available at January 1, 2018 228,279 Less: common stock purchased by eligible employees (20,120) Total ESPP equity securities available at January 1, 2019 208,159 Less: common stock purchased by eligible employees (23,299) Total ESPP equity securities available at January 1, 2020 184,860 Less: common stock purchased by eligible employees (35,661) Total ESPP equity securities available at December 31, 2020 149,199 Amounts withheld from participants will be classified as a liability on the Consolidated Balance Sheets until funds are used to purchase shares. This liability amount is immaterial to the consolidated financial statements. Stock-Based Compensation Expense Compensation expense associated with common stock, RSUs and restricted stock was recognized based on the grant date fair value of the instruments, over the instruments’ vesting period. The following table reflects stock-based compensation expense for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Performance-based RSUs $ 2,019 $ 1,434 $ 2,127 Time-based RSUs and restricted stock 3,389 2,119 2,756 ESPP 100 90 71 Total stock based compensation $ 5,508 $ 3,643 $ 4,954

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The significant components of our (provision for) benefit from income taxes attributable to current operations for the periods stated were as follows: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Loss before income taxes $ (21,770) $ (13,423) $ (2,185) Current: Federal tax — $ — $ — State tax 58 582 838 Foreign tax (150) 13 148 Total current (92) 595 986 Deferred: Federal tax 20,594 (2,121) (1,467) State tax 1,910 (1,239) (532) Foreign tax 43 107 307 Total deferred 22,547 (3,253) (1,692) (Provision for) benefit from income taxes $ 22,455 $ (2,658) $ (706) Foreign income before income tax (benefit) expense is immaterial to consolidated income before income tax (benefit) expense. The following table summarizes the principal elements of the difference between the United States federal statutory rate of 21% and our effective tax rate for the years ended December 31, 2020, 2019 and 2018: (Dollars in thousands) 2020 2019 2018 Loss before income taxes $ (21,770) $ (13,423) $ (2,185) Income taxes computed at the federal statutory rate $ (4,572) 21.0 % $ (2,819) 21.0 % $ (459) 21.0 % State income taxes, net of federal benefit (703) 3.2 % (567) 4.2 % 306 (14.0) % Goodwill impairment 6,341 (29.1) % 2,243 (16.7) % — — % Change in valuation allowance 22,108 (101.6) % — — % — — % Research and development and other tax credits (1,316) 6.0 % (1,790) 13.3 % (1,144) 52.4 % Excess executive compensation 266 (1.2) % 322 (2.4) % 281 (12.9) % Other 331 (1.5) % (47) 0.4 % 310 (14.2) % Provision for (benefit from) income taxes $ 22,455 (103.1) % $ (2,658) 19.8 % $ (706) 32.3 % The anticipated effective income tax rate is expected to continue to differ from the federal statutory rate primarily due to the effect of state incom e taxes, the benefit of the research and development tax credit, permanent differences between book and taxable income and certain discrete items. The earnings of non-U.S. subsidiaries are deemed to be indefinitely reinvested in non-U.S. operations. The components of deferred income tax assets at December 31, 2020, and 2019 were as follows: December 31, (Dollars in thousands) 2020 2019 Capitalized research and development costs $ 13,367 $ 18,605 Net operating loss carryforward 18,081 15,978 Property and equipment 5,353 6,092 Accrued liabilities, reserves and other expenses 5,063 3,718 Research and development credits 5,533 4,140 Tax credits 717 1,467 Stock based compensation 1,917 1,600 Other 132 121 Gross deferred income tax assets 50,163 51,721 Deferred income tax liabilities: Intangible assets (2,015) (2,430) Prepaid and other expenses (214) (308) Gross deferred income tax liabilities (2,229) (2,738) Net deferred income tax assets 47,934 48,983 Valuation allowance (22,108) — Total deferred income tax assets $ 25,826 $ 48,983 The Coronavirus Aid Relief and Economic Security ("CARES") Act was signed into law on March 27, 2020, to provide stimulus and relief in response to the COVID-19 pandemic and resulting economic collapse. While the CARES Act provides a number of potential benefits to companies, the Company has made use of the following provisions: • Payroll Tax Deferral: Allows for the deferral of payment on the Company's share of the 6.2% Social Security tax on wages paid beginning on March 27, 2020, and ending on December 31, 2020. Deferred amounts are payable in two installments, with 50% of such taxes due on December 31, 2021, and the remainder due on December 31, 2022. This resulted in a total deferral of $2.1 million in payroll taxes for the year ended December 31, 2020. • Employee Retention Credits: Allows for a refundable tax credit for the Company's share of the 6.2% Social Security tax on wages. This tax credit applies to the first $10,000 in qualified wages paid to each employee commencing on March 13, 2020. To be eligible, the Company must (i) have had operations fully or partially suspended because of a shutdown order from a governmental authority related to COVID-19, or (ii) have had gross receipts decline by more than 50% in a calendar quarter when compared to the same quarter in 2019. Qualified wages are limited to wages paid to employees who were not providing services due to the COVID-19 pandemic. This resulted in a tax credit of $1.3 million for the year ended December 31, 2020. • Alternative Minimum Tax ("AMT") Credit: Allows for an immediate refund of all refundable AMT credits resulting from passage of the CARES Act of 2020. This resulted in accelerated collection of approximately $1.3 million of other current assets that was received during the third quarter of 2020. Net Operating Losses As of December 31, 2020, we had approximately $79.7 million of net operating losses available to offset future taxable income, of which approximately $70.6 million were Federal net operating losses with expiration dates that begin expiring in 2026 and will fully expire in 2029. We have an immaterial amount of foreign tax credits available for future use. Valuation Allowance We assess the recoverability of our deferred income tax assets, which represent the tax benefits of future tax deductions, based on available positive and negative evidence and by considering the adequacy of future taxable income from all sources, including prudent and feasible tax planning strategies. This assessment is required to determine whether based on all available evidence, it is "more likely than not" (meaning a probability of greater than 50%) that all or some portion of the deferred income tax assets will be realized in future periods. The cumulative loss incurred by the Company over the three-year period ended December 31, 2020, constitutes a piece of objective negative evidence which limits our ability to consider other subjective evidence. In addition, the uncertainty created by COVID-19, has meaningfully limited our ability to consider our projections for future profitability and growth in our assessment of the recoverability of our deferred income tax assets. Based on this evaluation, which we completed utilizing our annual long-range planning and forecasting updates that are traditionally completed in the fourth quarter of each year, we recorded a valuation allowance of $22.1 million, as of December 31, 2020, to reduce net deferred income tax assets as their realization did not meet the more-likely-than-not criterion. COVID-19 has significantly limited our ability to consider projections for future profitability as objectively verifiable positive evidence to support the realizability of deferred tax assets, as the projections rely on subjective estimates and assumptions regarding the market launch of our SaaS product, Spok Go. As a result, a valuation allowance was established against deferred tax assets associated with net operating losses and credits with set expiration dates. Those deferred income tax assets which are not currently covered by a valuation allowance are those that are indefinite-lived, or whose temporary differences would reverse in the future and may result in the creation of an indefinite-lived deferred income tax asset, which we consider to be realized through future taxable income despite near term uncertainties. The amount of deferred income tax assets considered realizable, however, could be adjusted in the future if objective negative evidence in the form of cumulative losses is no longer present, additional weight is given to subjective evidence such as our projections for future profitability and growth, or other relevant factors arise. We did not record a valuation allowance during 2019 or 2018. Income Tax Audits The 2018, 2019 and 2020 federal and state income tax returns are within the statute of limitations (“SOL”) and are currently not under examination by any Federal or state tax authority. We operate in all states and the District of Columbia and are subject to various state income and franchise tax audits. The states’ SOL varies from three

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Contractual Obligations We had no significant commitments and contractual obligations as of December 31, 2020. Other Commitments We have various LOCs outstanding with multiple state agencies which are considered to be immaterial to the consolidated financial statements. The LOCs typically have one Legal Contingencies We are involved, from time to time, in lawsuits arising in the normal course of business. We believe the potential outcomes from these lawsuits will not have a material adverse impact on our financial position or statement of operations. Operating Leases We have operating leases for office and transmitter locations. Substantially all of these leases have lease terms ranging from one month to five years. We continue to review our office and transmitter locations, and intend to replace, reduce or consolidate leases, where possible. Future minimum lease payments under non-cancelable operating leases at December 31, 2020, were as follows: (Dollars in thousands) Operating Leases For the Year Ended December 31, 2021 $ 6,236 2022 4,541 2023 3,371 2024 1,879 2025 1,230 Thereafter 1,470 Total $ 18,727 These leases typically include renewal options and escalation clauses. Where material, we recognize rent expense on a straight-line basis over the lease period. Total rent expense under operating leases for the years ended December 31, 2020, 2019 and 2018, was approximately $17.3 million, $17.7 million and $17.5 million, respectively.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANSThe Company has a savings plan in the U.S., the Spok Holdings, Inc. Savings and Retirement Plan, which qualifies under Section 401(k) of the Internal Revenue Code. Participating U.S. employees may elect to contribute a percentage of their wages, subject to certain limitations. Matching contributions under the savings plan were approximately $1.6 million for the years ended December 31, 2020, 2019, and 2018

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES A former member of our Board of Directors, who departed the Board during the third quarter of 2020, also serves as a director for an entity that leases transmission tower sites to the Company. We incurred $3.5 million for the year ended December 31, 2020, and $3.6 million for the years ended December 31, 2019, and 2018 for site rent expense from the entity on which the individual serves as a director for each of the years ended December 31, 2020, 2019 and 2018. These amounts are included in technology operations expenses. A member of our Board of Directors who was appointed at the beginning of 2020 serves as Chief Information Officer for an entity that is also a customer of the Company. For the year ended December 31, 2020, we recognized revenues of $0.7 million related to contracts from the entity at which the individual is employed.

Selected Quarterly Financial In

Selected Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
SELECTED QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	SELECTED QUARTERLY FINANCIAL INFORMATION (UNAUDITED) Quarterly financial information for the years ended December 31, 2020, and 2019 is summarized below: For the Year Ended December 31, 2020 (Dollars in thousands except per share amounts) First Second Third Fourth Quarter (3) Revenues (1) $ 37,267 $ 35,739 $ 37,693 $ 37,480 Operating (loss) income (1) (4,108) 3,159 2,732 (24,449) Net (loss) income (1) (4,539) 3,759 3,165 (46,610) Basic net (loss) income per common share (2) (0.24) 0.20 0.17 (2.44) Diluted net (loss) income per common share (2) (0.24) 0.20 0.16 (2.44) For the Year Ended December 31, 2019 (Dollars in thousands except per share amounts) First Second Third Fourth Quarter (3)(4) Revenues (1) $ 41,764 $ 39,525 $ 39,453 $ 39,548 Operating income (loss) (1) 1,115 (1,992) (2,692) (12,239) Net income (loss) (1) 742 (670) (1,326) (9,511) Basic and diluted net income (loss) per common share (2) 0.04 (0.03) (0.07) (0.50) (1) Slight variations in totals are due to rounding. (2) Basic and diluted net income (loss) per common share is computed independently for each period presented. As a result, the sum of the quarterly basic and diluted net income (loss) per common share for the years ended December 31, 2020, and 2019 may not equal the total computed for the year. (3) The Company recorded a goodwill impairment of $25.0 million and $8.8 million during the fourth quarters of 2020 and 2019, respectively. See Note 6 "Goodwill and Intangible Assets, Net" for additional details.

VALUATION AND QUALIFYING ACCOUN

VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
VALUATION AND QUALIFYING ACCOUNTS	SCHEDULE II SPOK HOLDINGS, INC. VALUATION AND QUALIFYING ACCOUNTS Allowance for Doubtful Accounts, Service Credits and Other Balance at the Charged to Write-offs Balance at the (Dollars in thousands) Year ended December 31, 2020 $ 1,293 $ 1,382 $ (1,006) $ 1,669 Year ended December 31, 2019 $ 1,705 $ 1,248 $ (1,660) $ 1,293 Year ended December 31, 2018 $ 1,065 $ 2,125 $ (1,485) $ 1,705

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Business	We offer a focused suite of unified clinical communication and collaboration solutions that include call center operations, clinical alerting and notifications, one-way and advanced two-way wireless messaging services, mobile communications and public safety solutions. We provide one-way and advanced two-way wireless messaging services, including information services, throughout the United States. These services are offered on a local, regional and nationwide basis, employing digital networks. One-way messaging consists of numeric and alphanumeric messaging services. Numeric messaging services enable subscribers to receive messages that are composed entirely of numbers, such as a phone number, while alphanumeric messages may include numbers and letters, which enable subscribers to receive text messages. Two-way messaging services enable subscribers to send and receive messages to and from other wireless messaging devices, including pagers, personal digital assistants and personal computers. We also offer voice mail, personalized greetings, message storage and retrieval, and equipment loss and/or maintenance protection to both one-way and two-way messaging subscribers. These services are commonly referred to as wireless messaging and information services. We also develop, sell and support enterprise-wide systems for hospitals and other organizations needing to automate, centralize and standardize clinical communications. These solutions are used for contact centers, clinical alerting and notification, mobile communications and messaging and for public safety notifications. These areas of market focus compliment the market focus of our wireless services outlined above.
Basis of Presentation	Basis of Presentation The accompanying 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 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 Consolidated Financial Statements include all adjustments and accruals that are necessary for the presentation of the results of all periods reported herein and all such adjustments are of a normal, recurring nature, with the exception of our adoption of ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments, often referred to as Current Expected Credit Losses ("CECL"). For additional details refer to Note 2, "Recent Accounting Standards." Amounts shown on the consolidated statements of operations within the operating expense categories of cost of revenue; research and development; technology operations; selling and marketing; and general and administrative are recorded exclusive of depreciation, amortization and accretion. These items are shown separately on the Consolidated Statements of Operations within operating expenses to the extent that they are considered material for the periods presented. Certain immaterial prior period amounts in the consolidated financial statements have been reclassified to conform to the current period's presentation. These reclassifications had no effect on the reported results of operations or the statement of financial position.
Use of Estimates	Use of Estimates The preparation of these 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 ongoing 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, depreciation expense, asset retirement obligations, 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; Incremental Costs of Obtaining a Contract and Costs to Fulfill a Contract	Revenue Recognition 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 the product is delivered, when services begin and, to a lesser extent, when services are completed. For Software as a Service ("SaaS") contracts, the subscription and premium support services are generally billed annually in advance while professional services are billed at various milestones which reflect work 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 Consolidated Balance Sheets, primarily due to the receipt of payment in advance of the product or services we provide. Amounts billed and due from our customers are classified as accounts receivable on the Consolidated Balance Sheets. 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 Consolidated Financial Statements. 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 would not adjust the total consideration for the effects of a significant financing component if we anticipate, at contract inception, that the period between when we transfer a promised good or service to a customer and when the customer pays for that good or service will be one year or less. We account for a contract when: (1) both parties have approved the contract through mutually signed agreements or 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. Wireless service contracts are generally considered to be a single promise and therefore accounted for as a single performance obligation. Contracts which include goods or services related to our software solutions and subscriptions 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. Material performance obligations related to the sale of our SaaS platform include a SaaS subscription, professional services, and signature support services. 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 that 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 standalone selling price ("SSP") of the promised goods or services underlying each performance obligation. We rarely sell goods or services as 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, maintenance, and subscription 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 that include wireless, maintenance, or subscription 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 at completion ("EAC") for each contract. Our initial EAC is primarily based on prior experience also taking into consideration any specific facts and circumstances for a given contract. As projects progress, the EAC is periodically updated and reviewed to ensure the timing of revenue recognition is appropriate. The creation, maintenance and review of a project's EAC 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. 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. 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 undelivered 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
Leases	Leases Operating lease right-of-use ("ROU") assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. We have made an accounting policy election not to apply the recognition requirements of ASC 842, "Leases," to short-term leases. Those leases which have a term of less than 12 months will have lease payments recognized, in our Consolidated Statements of Operations, on a straight-line basis over the lease term. An optional renewal or termination is not recognized as part of the lease term unless we determine that it is reasonably certain that we will exercise that option. The term reasonably certain is a high threshold for which pervasive evidence generally does not exist, and therefore, optional renewal periods are generally excluded from our ROU assets and lease liabilities until they have been exercised. Lease expense is recognized on a straight-line basis over the lease term. As most of our leases do not provide an implicit rate, we use an estimated incremental borrowing rate in determining the present value of lease payments. The Company uses a portfolio approach when determining the discount rate applied to its leases. Significant judgment is necessary when determining a discount rate because we must estimate the discount rate based on a number of factors and observable inputs including current market conditions, market yields, government bond rates, credit risk, and other factors as necessary. The Company must also exercise significant judgment when determining whether an option to renew or terminate a lease should be included in the lease term. This judgment includes an assessment of all relevant economic factors such as costs relating to the termination or extension of a lease, importance of the underlying asset to the Company’s operations, and the terms and conditions of the optional periods in relation to current market rates. Where we have lease agreements which contain lease and non-lease components, we have elected to make use of the practical expedient to account for each separate lease component and associated non-lease component as a single lease component.
Impairment of Long-Lived Assets, Intangible Assets Subject to Amortization and Goodwill	Impairment of Long-Lived Assets, Intangible Assets Subject to Amortization and Goodwill We are required to evaluate the carrying value of our long-lived assets, amortizable intangible assets and goodwill. Amortizable intangible assets include customer-related intangibles that resulted from previous acquisitions. Such intangibles are amortized over periods up to ten years. Quarterly, we assess whether circumstances exist which suggest that the carrying value of long-lived and amortizable intangible assets may not be recoverable. When applicable, we assess the recoverability of the carrying value of our long-lived assets and certain amortizable intangible assets based on estimated undiscounted cash flows generated from such assets. In assessing the recoverability of these assets, we forecast estimated enterprise-level cash flows based on various operating assumptions such as revenue forecasted by product line and in-process research and development cost. If the forecast of undiscounted cash flows does not exceed the carrying value of the long-lived and amortizable intangible assets, we record an impairment charge to the extent the carrying value exceeded the fair value of such assets. Goodwill is not amortized but is evaluated for impairment at least annually, or when events or circumstances suggest a potential impairment has occurred. We generally perform this annual impairment test in the fourth quarter of the fiscal year. We evaluate goodwill for impairment between annual tests if indicators of impairment exist. The impairment test involves comparing the fair value of the reporting unit with its carrying value. An impairment charge is recognized for the amount that the carrying value exceeds the reporting unit's fair value. For purposes of the goodwill impairment evaluation, the Company as a whole is considered the reporting unit. The fair value of the reporting unit is estimated under a market-based approach using the fair value of the Company's common stock. The estimated fair value requires significant judgments, including timing and appropriateness of the price of common stock used (e.g. point-in-time application, simple moving average, exponential moving average), as well as application of an estimated control premium. The estimated control premium is based on a review of current and past market information published by a third-party resource, assessment of the Company's future projected discounted cash flows and other relevant information if available.
Accounts Receivable Allowances	Accounts Receivable Allowances Our two most significant allowance accounts are: an allowance for doubtful accounts and an allowance for service credits. Provisions for these allowances are recorded on a monthly basis and are included as a component of general and administrative expenses, respectively. Estimates are used in determining the allowance for doubtful accounts and are based on historical collection experience and current and forecasted trends, as well as known specific collection risks. In determining these estimates, we review historical write-offs, including comparisons of write-offs to provisions for doubtful accounts. We compare the ratio of the allowance to gross receivables to historical levels, and monitor amounts collected and related statistics. We write off receivables when they are deemed uncollectible. While write-offs of customer accounts have historically been within our expectations and the provisions established, we cannot guarantee that the future write-off experience will be consistent with historical experience, which could result in material differences when compared to the allowance for doubtful accounts and related provisions. From time to time, we grant service credits for customer retention purposes or when there is an adjustment in the scope of work. The allowance for service credits related provisions are based on historical credit percentages, current credit and aging trends, historical actual payment trends and actual credit experience. We analyze our past credit experience over several time frames. Using this analysis along with current operational data, including existing experience of credits issued and the time frames in which credits are issued, we establish an appropriate allowance for service credits. This allowance also reduces accounts receivable for lost and non-returned pagers to the expected realizable amounts and for free wireless services. While credits issued have been within our expectations and the provisions established, we cannot guarantee that future credit experience will be consistent with historical experience, which could result in material differences when compared to the allowance for service credits and maintenance-related provisions.
Inventory	Inventory Inventories are stated at the lower of cost or net realizable value. Cost is computed using a weighted average cost approach which averages the prices at which goods are purchased from vendors. We evaluate our ending inventories for shrinkage and estimated obsolescence. Any shrinkage identified is written off to cost of goods sold in the period in which the shrinkage is identified. Further, we assess the impact of changing technology on our inventories and we write off inventories that are considered obsolete in the period in which the analysis takes place. Inventory consists primarily of finished goods. We do not account for inventory as work-in-process or raw materials as any such inventory would be immaterial to the consolidated financial statements.
Property and Equipment	Property and Equipment Property and equipment are reported at cost and are depreciated using the straight-line method based on estimated useful lives which range from one
Asset Retirement Obligations	Asset Retirement Obligations We recognize liabilities and corresponding assets for future obligations associated with the retirement of assets. We have paging equipment assets, principally transmitters, which are located at leased locations. The underlying leases generally require the removal of equipment at the end of the lease term; therefore, a future obligation exists. Asset retirement costs are reflected in paging equipment assets with depreciation expense recognized over the estimated lives, which range between one The recognition of an asset retirement obligation requires that management make numerous assumptions regarding such factors as the cost and timing of deconstruction; the credit-adjusted risk-free rate to be used; inflation rates; and future advances in technology. The fair value estimate of contractor fees to remove each asset is assumed to escalate by 2% each year through the terminal date. The total estimated liability is based on the estimated future value of those costs and the timing of deconstruction. We believe these estimates are reasonable at the present time, but we can give no assurance that changes in technology, our financial condition, the economy or other factors would not result in higher or lower asset retirement obligations. Any variations from our estimates would generally result in a change in the assets and liabilities in equal amounts, and operating results would differ in the future by any difference in depreciation expense and accretion expense (see Note 5, "Consolidated Financial Statement Components", and Note 7, "Asset Retirement Obligations" for additional details).
Income Taxes	Income Taxes We file a consolidated U.S. federal income tax return and income tax returns in state, local and foreign jurisdictions as required. The provision for current income taxes is calculated and accrued on income and expenses expected to be included in current year U.S. and foreign income tax returns. The provision for current income taxes may also include interest, penalties and an estimated amount reflecting uncertain tax positions. Deferred income tax assets and liabilities are calculated based on temporary differences between the financial statement values and the tax bases of assets and liabilities including net operating loss and tax credit carryforwards at the enacted tax rates expected to apply to taxable income when taxes are actually paid or recovered. Changes in deferred income tax assets and liabilities are included as a component of deferred income tax expense. Deferred income tax assets represent amounts available to reduce future income taxes payable. We assess the recoverability of our deferred income tax assets, which represent the tax benefits of future tax deductions, based on available positive and negative evidence and by considering the adequacy of future taxable income from all sources, including prudent and feasible tax planning strategies. This assessment is required to determine whether based on all available evidence, it is "more likely than not" (meaning a probability of greater than 50%) that all or some portion of the deferred income tax assets will be realized in future periods. We provide a valuation allowance when we consider it "more likely than not" that a deferred income tax asset will not be fully recovered. The assessment of our deferred income tax assets requires significant judgment.
Research and Development	Research and Development In accordance with ASC 985-20, Software to be Sold, Leased, or Marketed, certain software development costs are charged to operations and expensed as incurred until technological feasibility has been established. Material costs incurred after technological feasibility is established and before the product is ready for general release are capitalized and amortized on a straight-line basis over the estimated remaining economic life of the product or the ratio of current revenues to total projected product revenues, whichever is greater. To date, the time between technological feasibility and general release to the public has been extremely short and consequently expenses available for capitalization have been immaterial. Accordingly, all research and developments costs incurred to date, accounted for in accordance with ASC 985-20, have been expensed as incurred. In accordance with ASC 350-40, Internal-Use Software, certain software development costs are capitalized while in the application development stage related to software developed for internal use or software sold in a Software as a Service ("SaaS") arrangement. This includes certain development costs for Spok Go which qualified for capitalization beginning in the first quarter of 2020. All other costs incurred during the preliminary project stage or the post-implementation stage, are expensed as incurred. Significant judgment is required when assessing costs and determining whether they fall within the preliminary project, application development, or post-implementation stage that determines whether the associated costs are expensed as incurred or capitalized. Capitalized software development is amortized on a straight-line basis over the estimated useful life of the asset, typically three years, beginning when those development efforts have been placed into service (e.g., generally once made commercially available). Determining the estimated useful life requires significant judgment as we consider factors such as the rapid and continuous developments in software technology, obsolescence and anticipated life of the service offering before enhancements are necessary. In a SaaS environment, customer needs are rapidly evolving and a shorter useful life is generally expected.
Advertising Expenses	Advertising ExpensesAdvertising costs are charged to operations when incurred. Advertising costs are classified as selling and marketing expenses.
Stock Based Compensation	Stock-Based Compensation We account for share-based payments to employees, including restricted stock units ("RSUs"), restricted common stock ("restricted stock") and the option to purchase common stock under the Employee Stock Purchase Plan ("ESPP") based on their fair value and the estimated number of shares we expect will vest based on the performance metrics associated with the award, if applicable. Fair value is measured based on the closing fair market value of the Company's common stock on the date of grant. Compensation expense is recognized on a straight-line basis over the requisite service period. Forfeitures and withdrawals are accounted for on an as incurred basis. Changes in our estimates of the expected attainment of performance targets are reflected in the amount of compensation expense that we recognize for the related instruments during the interim reporting period when the change in estimate is determined and may cause the amount of compensation expense that we record for each period to vary. Further information regarding stock-based compensation can be found in Note 8, "Stockholders' Equity."
Concentration of Credit Risk	Concentration of Credit Risk Our financial instruments that are potentially subject to concentrations of credit risk consist primarily of cash, cash equivalents, short-term receivables and accounts receivable. While our cash and cash equivalents are managed by reputable financial institutions, deposits at these institutions and funds may, at times, exceed federally insured limits. Management believes that these financial institutions and funds are financially sound and, accordingly, that minimal credit risk exists.
Sales and Use Taxes	Sales and Use Taxes Sales and use taxes imposed on the ultimate consumer are excluded from revenue where we are required by law or regulation to act as collection agent for the taxing jurisdiction.
Fair Value Measurements and Financial Instruments	Fair Value Measurements and Financial Instruments We account for certain assets and liabilities at fair value. We categorize each of our fair value measurements in one of the following three levels based on the lowest level input that is significant to the fair value measurement in its entirety. These levels are: • Level 1 : Inputs are based upon unadjusted quoted prices for identical instruments in active markets. • Level 2 : Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are corroborated by other observable market data. • Level 3 : Unobservable inputs that cannot be corroborated by observable market data and typically reflect management's estimates of assumptions that market participants would use in pricing the asset or liability. We consider all highly liquid interest-earning investments with a maturity of three months or less at the date of purchase to be cash equivalents. Those investments with an original maturity of greater than three months and less than one year are classified as short-term investments. Cash and cash equivalents consist primarily of cash on deposit with banks and investments in money market funds. Our short-term investments consist entirely of U.S. Treasury securities which are classified as held-to-maturity and are measured at amortized cost on our Consolidated Balance Sheets. These investments are classified as Level 1 and mature within 12 months. The differences between carrying value and fair value are not material to the Consolidated Financial Statements. Financial instruments including cash and cash equivalents, accounts receivable and accounts payable all have fair values that approximate their carrying values at December 31, 2020, and 2019 due to their short maturities.
Earnings Per Common Share	Earnings Per Common Share The calculation of earnings per common share is based on the weighted-average number of common shares outstanding during the applicable period. The calculation for diluted earnings per common share recognizes the effect of all potentially dilutive common shares that were outstanding during the respective periods, unless the impact would be anti-dilutive. Further information regarding earnings per common share can be found in Note 8 , "Stockholders' Equity."
Recent Accounting Standards	RECENT ACCOUNTING STANDARDSIn June 2016, the Financial Accounting Standards Board issued ASU No. 2016-13, or CECL. CECL requires early recognition of credit losses on financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. This guidance is effective for fiscal years beginning after December 15, 2019. On January 1, 2020, we adopted ASU No. 2016-13 which resulted in an immaterial adjustment to the beginning balance of retained earnings and an increase to allowance for doubtful accounts.

Revenue, Deferred Revenue and_2

Revenue, Deferred Revenue and Prepaid Commissions (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Revenue	The following table presents our revenues disaggregated by revenue type: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Revenue - wireless: Paging revenue $ 79,916 $ 85,067 $ 90,570 Product and other revenue 3,677 3,100 3,707 Total wireless revenue $ 83,593 $ 88,167 $ 94,277 Revenue - software: License $ 5,179 $ 8,950 $ 13,042 Services 17,910 19,189 18,091 Equipment 2,841 3,618 4,995 Subscription 66 — — Operations revenue 25,996 31,757 36,128 Maintenance revenue 38,591 40,365 39,069 Total software revenue $ 64,587 $ 72,122 $ 75,197 Total revenue $ 148,180 $ 160,289 $ 169,474 The Company is currently structured as a single operating (and reportable) segment, a clinical communication and collaboration business. The U.S. was the only country that accounted for more than 10% of the Company’s total revenue for the years ended December 31, 2020, 2019 and 2018. Revenue generated in the U.S. and internationally consisted of the following for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Revenue: United States $ 145,349 $ 154,766 $ 164,558 International 2,831 5,523 4,916 Total revenue $ 148,180 $ 160,289 $ 169,474
Schedule of Deferred Revenue	Changes in the balance of total deferred revenue during the twelve months ended December 31, 2020, are as follows: (Dollars in thousands) December 31, 2019 Additions Revenue Recognized December 31, 2020 Deferred Revenue $ 26,621 $ 67,769 $ (64,594) $ 29,796
Schedule of Deferred Commissions	Changes in the balance of total prepaid commissions during the year ended December 31, 2020, are as follows: (Dollars in thousands) December 31, 2019 Additions Commissions Recognized December 31, 2020 Prepaid Commissions $ 2,431 $ 4,160 (4,301) $ 2,290

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Lease Costs	The following table presents lease costs disaggregated by type: For the Year Ended December 31, (Dollars in thousands) 2020 2019 Operating lease cost $ 5,797 $ 5,823 Short-term lease cost 7,991 8,281 Short-term lease cost - related party (1) 3,518 3,589 Total lease cost $ 17,306 $ 17,693 Supplemental Disclosure: Cash paid for amounts included in the measurement of lease liabilities - operating leases $ 5,685 $ 5,678 Weighted-average remaining lease term - operating leases (in years) 5.06 5.60 Weighted-average discount rate - operating leases 5.17% 5.45% (1) A former member of our Board of Directors, who departed our Board during the third quarter of 2020, also serves as a director for an entity that leases transmission tower sites to the Company. Refer to Note 12, "Related Parties" for additional details.
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of December 31, 2020, were as follows: (Dollars in thousands) For the Year Ended December 31, 2021 $ 5,273 2022 3,539 2023 2,395 2024 1,672 2025 1,050 Thereafter 2,816 Total future lease payments 16,745 Imputed interest (2,025) Total $ 14,720 Future minimum lease payments under non-cancelable operating leases at December 31, 2020, were as follows: (Dollars in thousands) Operating Leases For the Year Ended December 31, 2021 $ 6,236 2022 4,541 2023 3,371 2024 1,879 2025 1,230 Thereafter 1,470 Total $ 18,727

Consolidated Financial Statem_2

Consolidated Financial Statements' Components (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Depreciation, Amortization and Accretion	Depreciation, amortization and accretion consisted of the following for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Depreciation Leasehold improvements $ 57 $ 63 $ 232 Asset retirement costs (643) (766) (300) Paging and computer equipment 5,291 6,526 7,397 Furniture, fixtures and vehicles 307 374 398 Total depreciation 5,012 6,197 7,727 Amortization Intangible assets 2,500 2,500 2,500 Capitalized software development costs 1,073 — — Total amortization 3,573 2,500 2,500 Accretion 471 552 542 Total depreciation, amortization and accretion expense $ 9,056 $ 9,249 $ 10,769
Property, Plant and Equipment	Property and equipment, net consisted of the following for the periods stated: Useful Life For the Year Ended December 31, (Dollars in thousands) 2020 2019 Leasehold improvements lease term $ 3,628 $ 3,620 Asset retirement costs 1-5 3,717 1,922 Paging and computer equipment 1-5 92,608 96,562 Furniture, fixtures and vehicles 3-5 3,517 3,716 Total property and equipment 103,470 105,820 Accumulated depreciation (95,655) (97,820) Total property and equipment, net $ 7,815 $ 8,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Change in Goodwill	The change in goodwill for the year ended December 31, 2020, was as follows: (Dollars in thousands) Change in Goodwill Goodwill at January 1, 2019 $ 133,031 Impairment $ (8,849) Goodwill at January 1, 2020 $ 124,182 Impairment (25,007) Goodwill at December 31, 2020 $ 99,175
Summary of Amortizable Intangible Assets	The net consolidated balance of intangible assets consisted of the following at December 31, 2020, and 2019: As of December 31, 2020 2019 (Dollars in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer relationships $ 25,002 $ (24,585) $ 417 $ 25,002 $ (22,085) $ 2,917

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Summary of Changes in Asset Retirement Obligation Liability Balances	The components of the changes in the asset retirement obligation liabilities for the periods stated were as follows: (Dollars in thousands) Short-Term Portion Long-Term Portion Total Balance at January 1, 2019 $ 34 $ 6,513 $ 6,547 Accretion 39 513 552 Amounts paid (177) — (177) Additions — 32 32 Reductions 14 (817) (803) Reclassifications 180 (180) — Balance at December 31, 2019 90 6,061 6,151 Accretion (38) 509 471 Amounts paid (352) — (352) Additions 169 1,185 1,354 Reclassifications 466 (466) — Balance at December 31, 2020 $ 335 $ 7,289 $ 7,624

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Common Stock Purchased Including Purchase of Common Stock for Tax Withholdings	The Company did not repurchase any of its common stock during 2020. Common stock repurchased in 2019 and 2018 (excluding commission and the purchase of common stock for tax withholdings) was as follows: (Dollars in thousands, except for shares purchased) 2019 2018 For the Three Months Ended Shares Purchased Amount Shares Purchased Amount March 31, 131,012 $ 1,806 127,792 $ 1,922 June 30, — — 501,782 7,520 September 30, 401,342 4,749 36,542 558 December 31, — — 263,000 3,446 Total 532,354 $ 6,555 929,116 $ 13,446
Schedule of Earnings Per Share, Basic and Diluted	The components of basic and diluted net loss per common share were as follows for the periods stated: For the Year Ended December 31, (In thousands, except for share and per share amounts) 2020 2019 2018 Numerator: Net loss $ (44,225) $ (10,765) $ (1,479) Denominator: Basic and diluted weighted average outstanding shares of common stock 19,028,918 19,089,402 19,667,891 Basic and diluted net loss per common share $ (2.32) $ (0.56) $ (0.08)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	For the years ended December 31, 2020, 2019 and 2018, the following securities were not included in the calculation of diluted shares outstanding as the effect would have been anti-dilutive: For the Year Ended December 31, 2020 2019 2018 Restricted stock units 297,757 189,862 178,279
Activities Under Equity Plan	The following table summarizes the activities under the Equity Plans from January 1, 2018, through December 31, 2020: Activity Total equity securities available at January 1, 2018 1,140,658 Less: RSU and restricted stock awarded to eligible employees, net of forfeitures (236,221) Total equity securities available at December 31, 2018 904,437 Less: RSU and restricted stock awarded to eligible employees, net of forfeitures (257,957) Total equity securities available at December 31, 2019 646,480 Less: RSU, DSU and restricted stock awarded to eligible employees, net of forfeitures (547,166) Plus: Additional shares available for issuance under the 2020 Equity Plan 1,600,000 Total equity securities available at December 31, 2020 1,699,314
Additional Awards Under 2011 LTIP	The following table details activities with respect to outstanding RSUs, DSUs, and restricted stock under the Equity Plans for the year ended December 31, 2020: Shares Weighted-Average Grant Date Fair Value per Share Unvested at January 1, 2020 419,426 $ 14.00 Granted 603,171 11.94 Vested (329,870) 14.05 Forfeited (56,005) 12.49 Unvested at December 31, 2020 636,722 $ 12.16
Activities Under Equity Plan From Inception	The following table summarizes the activities under the ESPP from January 1, 2018, through December 31, 2020: Activity Total ESPP equity securities available at January 1, 2018 228,279 Less: common stock purchased by eligible employees (20,120) Total ESPP equity securities available at January 1, 2019 208,159 Less: common stock purchased by eligible employees (23,299) Total ESPP equity securities available at January 1, 2020 184,860 Less: common stock purchased by eligible employees (35,661) Total ESPP equity securities available at December 31, 2020 149,199
Summary of Stock Based Compensation Expense	The following table reflects stock-based compensation expense for the periods stated: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Performance-based RSUs $ 2,019 $ 1,434 $ 2,127 Time-based RSUs and restricted stock 3,389 2,119 2,756 ESPP 100 90 71 Total stock based compensation $ 5,508 $ 3,643 $ 4,954

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components of Income Tax Expense (Benefit) Attributable to Current Operations	The significant components of our (provision for) benefit from income taxes attributable to current operations for the periods stated were as follows: For the Year Ended December 31, (Dollars in thousands) 2020 2019 2018 Loss before income taxes $ (21,770) $ (13,423) $ (2,185) Current: Federal tax — $ — $ — State tax 58 582 838 Foreign tax (150) 13 148 Total current (92) 595 986 Deferred: Federal tax 20,594 (2,121) (1,467) State tax 1,910 (1,239) (532) Foreign tax 43 107 307 Total deferred 22,547 (3,253) (1,692) (Provision for) benefit from income taxes $ 22,455 $ (2,658) $ (706)
Schedule of Effective Income Tax Rate Reconciliation	The following table summarizes the principal elements of the difference between the United States federal statutory rate of 21% and our effective tax rate for the years ended December 31, 2020, 2019 and 2018: (Dollars in thousands) 2020 2019 2018 Loss before income taxes $ (21,770) $ (13,423) $ (2,185) Income taxes computed at the federal statutory rate $ (4,572) 21.0 % $ (2,819) 21.0 % $ (459) 21.0 % State income taxes, net of federal benefit (703) 3.2 % (567) 4.2 % 306 (14.0) % Goodwill impairment 6,341 (29.1) % 2,243 (16.7) % — — % Change in valuation allowance 22,108 (101.6) % — — % — — % Research and development and other tax credits (1,316) 6.0 % (1,790) 13.3 % (1,144) 52.4 % Excess executive compensation 266 (1.2) % 322 (2.4) % 281 (12.9) % Other 331 (1.5) % (47) 0.4 % 310 (14.2) % Provision for (benefit from) income taxes $ 22,455 (103.1) % $ (2,658) 19.8 % $ (706) 32.3 %
Schedule of Deferred Income Tax Assets	The components of deferred income tax assets at December 31, 2020, and 2019 were as follows: December 31, (Dollars in thousands) 2020 2019 Capitalized research and development costs $ 13,367 $ 18,605 Net operating loss carryforward 18,081 15,978 Property and equipment 5,353 6,092 Accrued liabilities, reserves and other expenses 5,063 3,718 Research and development credits 5,533 4,140 Tax credits 717 1,467 Stock based compensation 1,917 1,600 Other 132 121 Gross deferred income tax assets 50,163 51,721 Deferred income tax liabilities: Intangible assets (2,015) (2,430) Prepaid and other expenses (214) (308) Gross deferred income tax liabilities (2,229) (2,738) Net deferred income tax assets 47,934 48,983 Valuation allowance (22,108) — Total deferred income tax assets $ 25,826 $ 48,983

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of December 31, 2020, were as follows: (Dollars in thousands) For the Year Ended December 31, 2021 $ 5,273 2022 3,539 2023 2,395 2024 1,672 2025 1,050 Thereafter 2,816 Total future lease payments 16,745 Imputed interest (2,025) Total $ 14,720 Future minimum lease payments under non-cancelable operating leases at December 31, 2020, were as follows: (Dollars in thousands) Operating Leases For the Year Ended December 31, 2021 $ 6,236 2022 4,541 2023 3,371 2024 1,879 2025 1,230 Thereafter 1,470 Total $ 18,727

Selected Quarterly Financial _2

Selected Quarterly Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Summarized Quarterly Data	Quarterly financial information for the years ended December 31, 2020, and 2019 is summarized below: For the Year Ended December 31, 2020 (Dollars in thousands except per share amounts) First Second Third Fourth Quarter (3) Revenues (1) $ 37,267 $ 35,739 $ 37,693 $ 37,480 Operating (loss) income (1) (4,108) 3,159 2,732 (24,449) Net (loss) income (1) (4,539) 3,759 3,165 (46,610) Basic net (loss) income per common share (2) (0.24) 0.20 0.17 (2.44) Diluted net (loss) income per common share (2) (0.24) 0.20 0.16 (2.44) For the Year Ended December 31, 2019 (Dollars in thousands except per share amounts) First Second Third Fourth Quarter (3)(4) Revenues (1) $ 41,764 $ 39,525 $ 39,453 $ 39,548 Operating income (loss) (1) 1,115 (1,992) (2,692) (12,239) Net income (loss) (1) 742 (670) (1,326) (9,511) Basic and diluted net income (loss) per common share (2) 0.04 (0.03) (0.07) (0.50) (1) Slight variations in totals are due to rounding. (2) Basic and diluted net income (loss) per common share is computed independently for each period presented. As a result, the sum of the quarterly basic and diluted net income (loss) per common share for the years ended December 31, 2020, and 2019 may not equal the total computed for the year. (3) The Company recorded a goodwill impairment of $25.0 million and $8.8 million during the fourth quarters of 2020 and 2019, respectively. See Note 6 "Goodwill and Intangible Assets, Net" for additional details.

Organization and Significant _3

Organization and Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)account	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Property, Plant and Equipment [Line Items]
Commissions expense	$ 4,300,000	$ 5,000,000	$ 6,200,000
Impairment of intangible assets	$ 0	0	0
Number of significant allowance accounts | account	2
Contractor fee, annual percentage increase	2.00%
Uncertain tax positions	$ 0	0
Advertising expenses	1,300,000	1,700,000	2,400,000
Provisions for doubtful accounts, service credits and other	$ 1,100,000	$ 700,000	$ 1,600,000
Customer relationships
Property, Plant and Equipment [Line Items]
Amortization of intangible assets	10 years
Maximum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Minimum
Property, Plant and Equipment [Line Items]
Useful life	1 year
Paging Equipment Assets | Maximum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Paging Equipment Assets | Minimum
Property, Plant and Equipment [Line Items]
Useful life	1 year
Capitalized software development costs
Property, Plant and Equipment [Line Items]
Useful life	3 years

Revenue, Deferred Revenue and_3

Revenue, Deferred Revenue and Prepaid Commissions - Schedule of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 37,480	$ 37,693	$ 35,739	$ 37,267	$ 39,548	$ 39,453	$ 39,525	$ 41,764	$ 148,180	$ 160,289	$ 169,474
United States
Disaggregation of Revenue [Line Items]
Revenues									145,349	154,766	164,558
International
Disaggregation of Revenue [Line Items]
Revenues									2,831	5,523	4,916
Total wireless revenue
Disaggregation of Revenue [Line Items]
Revenues									83,593	88,167	94,277
Paging revenue
Disaggregation of Revenue [Line Items]
Revenues									79,916	85,067	90,570
Product and other revenue
Disaggregation of Revenue [Line Items]
Revenues									3,677	3,100	3,707
Total software revenue
Disaggregation of Revenue [Line Items]
Revenues									64,587	72,122	75,197
Operations revenue
Disaggregation of Revenue [Line Items]
Revenues									25,996	31,757	36,128
License
Disaggregation of Revenue [Line Items]
Revenues									5,179	8,950	13,042
Services
Disaggregation of Revenue [Line Items]
Revenues									17,910	19,189	18,091
Equipment
Disaggregation of Revenue [Line Items]
Revenues									2,841	3,618	4,995
Subscription
Disaggregation of Revenue [Line Items]
Revenues									66	0	0
Maintenance revenue
Disaggregation of Revenue [Line Items]
Revenues									$ 38,591	$ 40,365	$ 39,069

Revenue, Deferred Revenue and_4

Revenue, Deferred Revenue and Prepaid Commissions - Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contract With Customer, Asset And Liability [Roll Forward]
Beginning balance	$ 26,621
Additions	3,175	$ 42	$ (866)
Ending balance	29,796	$ 26,621
Accounting Standards Update 2014-09
Contract With Customer, Asset And Liability [Roll Forward]
Additions	67,769
Revenue Recognized	$ (64,594)

Revenue, Deferred Revenue and_5

Revenue, Deferred Revenue and Prepaid Commissions - Additional Details (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 24.7
Remaining performance obligation	$ 50.5

Revenue, Deferred Revenue and_6

Revenue, Deferred Revenue and Prepaid Commissions - Deferred Commissions (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Capitalized Contract Cost [Roll Forward]
Commissions Recognized	$ (4,301)
Sales Commissions
Capitalized Contract Cost [Roll Forward]
Beginning balance	2,431
Additions	4,160
Ending balance	$ 2,290

Revenue, Deferred Revenue and_7

Revenue, Deferred Revenue and Prepaid Commissions - Performance Obligations (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 50.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 37
Remaining performance obligation, timing	12 months

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)ft²	Dec. 31, 2020USD ($)renewal	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Termination term		1 year
Operating lease right-of-use assets		$ 14,016	$ 16,317
Operating lease liabilities		$ 14,720
Forecast
Lessee, Lease, Description [Line Items]
Area lease | ft²	26,000
Operating lease right-of-use assets	$ 4,400
Operating lease liabilities	$ 4,400
Minimum
Lessee, Lease, Description [Line Items]
Number of renewal options | renewal		1
Maximum
Lessee, Lease, Description [Line Items]
Number of renewal options | renewal		5

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 5,797	$ 5,823
Short-term lease cost	7,991	8,281
Short-term lease cost - related party	3,518	3,589
Total lease cost	17,306	17,693
Cash paid for amounts included in the measurement of lease liabilities - operating leases	$ 5,685	$ 5,678
Weighted-average remaining lease term - operating leases (in years)	5 years 21 days	5 years 7 months 6 days
Weighted-average discount rate - operating leases	5.17%	5.45%

Leases - Lease Maturities (Deta

Leases - Lease Maturities (Details) $ in Thousands	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 5,273
2022	3,539
2023	2,395
2024	1,672
2025	1,050
Thereafter	2,816
Total	16,745
Imputed interest	(2,025)
Total	$ 14,720

Consolidated Financial Statem_3

Consolidated Financial Statements' Components - Depreciation, Amortization and Accretion (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total depreciation	$ 5,012,000	$ 6,197,000	$ 7,727,000
Intangible assets	2,500,000	2,500,000	2,500,000
Capitalized software development costs	1,073,000	0	0
Total amortization	3,573,000	2,500,000	2,500,000
Accretion	471,000	552,000	542,000
Total depreciation, amortization and accretion expense	9,056,000	9,249,000	10,769,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total depreciation	57,000	63,000	232,000
Asset retirement costs
Property, Plant and Equipment [Line Items]
Total depreciation	(643,000)	(766,000)	(300,000)
Paging and computer equipment
Property, Plant and Equipment [Line Items]
Total depreciation	5,291,000	6,526,000	7,397,000
Furniture, fixtures and vehicles
Property, Plant and Equipment [Line Items]
Total depreciation	$ 307,000	$ 374,000	$ 398,000

Consolidated Financial Statem_4

Consolidated Financial Statements' Components - Accounts Receivable, net (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Allowances for doubtful accounts	$ (1.7)	$ (1.3)
Unbilled receivables	$ 7	$ 6.4

Consolidated Financial Statem_5

Consolidated Financial Statements' Components - Property and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 103,470	$ 105,820
Accumulated depreciation	(95,655)	(97,820)
Total property and equipment, net	$ 7,815	8,000
Minimum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	1 year
Maximum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,628	3,620
Asset retirement costs
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,717	1,922
Asset retirement costs | Minimum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	1 year
Asset retirement costs | Maximum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	5 years
Paging and computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 92,608	96,562
Paging and computer equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	1 year
Paging and computer equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	5 years
Furniture, fixtures and vehicles
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 3,517	$ 3,716
Furniture, fixtures and vehicles | Minimum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	3 years
Furniture, fixtures and vehicles | Maximum
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	5 years

Consolidated Financial Statem_6

Consolidated Financial Statements' Components - Capitalized Software (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Capitalized software development costs	$ (11,300,000)	$ 0
Capitalized software development costs, amortization expense	$ 1,073,000	$ 0	$ 0
Software Development
Property, Plant and Equipment [Line Items]
Useful Life (In Years)	3 years

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, Net - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill at January 1, 2020			$ 124,182	$ 133,031
Impairment	$ (8,800)	$ (25,000)	(25,007)	(8,849)	$ 0
Goodwill at December 31, 2020	$ 99,175	$ 124,182	$ 99,175	$ 124,182	$ 133,031

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, Net - Net Intangible Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Impairment	$ 0	$ 0	$ 0
Remaining amortization for 2021	400,000
Net Carrying Amount	$ 417,000	2,917,000
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Useful Life (In Years)	10 years
Gross Carrying Amount	$ 25,002,000	25,002,000
Accumulated Amortization	(24,585,000)	(22,085,000)
Net Carrying Amount	$ 417,000	$ 2,917,000

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Asset Retirement Obligation
Balance	$ 6,151	$ 6,547
Accretion	471	552	$ 542
Amounts paid	(352)	(177)
Additions	1,354	32
Reductions		(803)
Reclassifications	0	0
Balance	7,624	6,151	6,547
Total estimated liability	9,300
Short-Term Portion
Asset Retirement Obligation
Balance	90	34
Accretion	(38)	39
Amounts paid	(352)	(177)
Additions	169	0
Reductions		14
Reclassifications	466	180
Balance	335	90	34
Long-Term Portion
Asset Retirement Obligation
Balance	6,061	6,513
Accretion	509	513
Amounts paid	0	0
Additions	1,185	32
Reductions		(817)
Reclassifications	(466)	(180)
Balance	$ 7,289	$ 6,061	$ 6,513

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 17, 2021	Jul. 28, 2020	Aug. 31, 2018	Jul. 25, 2016	May 16, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (shares)	75,000,000	75,000,000
Common stock par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (shares)	25,000,000	25,000,000
Preferred stock par value (usd per share)	$ 0.0001	$ 0.0001
Stock options outstanding (shares)	0	0
Common stock outstanding (shares)	19,384,192	19,071,614
Preferred stock outstanding (shares)	0	0
Dividends declared (usd per share)	$ 0.50	$ 0.50	$ 0.50
Common stock repurchase program, authorized amount						$ 10,000,000
Shares reserved for future issuance (in shares)					1,699,950
Unvested shares outstanding (shares)	605,606
Common stock, share price (usd per share)		$ 12.23	$ 13.26
Issuance of common stock under the Employee Stock Purchase Plan	$ 300,000	$ 264,000	$ 247,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)		388,321	343,102
Granted (usd per share)		$ 13.27	$ 15.65
Fair value of shares vested		$ 3,000,000	$ 2,700,000
2012 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity securities granted (shares)								2,194,986
Granted (shares)	547,166	257,957	236,221
2012 Equity Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
2012 Equity Plan | Contingent restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
2012 Equity Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
2011 Long Term Incentive Plan | Restricted Stock and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized	$ 4,100,000
Compensation cost not yet recognized, period for recognition	1 year 7 months 6 days
2011 Long Term Incentive Plan | Contingent restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested shares outstanding (shares)	354,125
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity securities granted (shares)							250,000
Award required holding period	2 years
Issuance of common stock under the Employee Stock Purchase Plan (shares)	35,661	23,299
Issuance of common stock under the Employee Stock Purchase Plan	$ 300,000	$ 300,000
Maximum | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Offering period	6 months
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend rate (usd per share)				$ 0.125
Dividends declared				$ 2,400,000
Tranche one | 2012 Equity Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	33.00%
Tranche two | 2012 Equity Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	33.00%
Tranche three | 2012 Equity Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	33.00%

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Purchased Including Purchase of Common Stock for Tax Withholdings (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Shares purchased (shares)	0	401,342	0	131,012	263,000	36,542	501,782	127,792	532,354	929,116
Amount	$ 0	$ 4,749	$ 0	$ 1,806	$ 3,446	$ 558	$ 7,520	$ 1,922	$ 6,555	$ 13,446

Stockholders' Equity - Earnings

Stockholders' Equity - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss	$ (46,610)	$ 3,165	$ 3,759	$ (4,539)	$ (9,511)	$ (1,326)	$ (670)	$ 742	$ (44,225)	$ (10,765)	$ (1,479)
Denominator:
Basic and diluted weighted average outstanding shares of common stock (shares)									19,028,918	19,089,402	19,667,891
Basic and diluted net loss per common share (usd per share)					$ (0.50)	$ (0.07)	$ (0.03)	$ 0.04	$ (2.32)	$ (0.56)	$ (0.08)
Restricted stock units
Denominator:
Restricted stock units (shares)									297,757	189,862	178,279

Stockholders' Equity - Activiti

Stockholders' Equity - Activities Under Equity Plan (Details) - 2012 Equity Plan - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Shares Available for Grant [Roll Forward]
Beginning Balance, Equity securities available (shares)	646,480	904,437	1,140,658
Granted (shares)	(547,166)	(257,957)	(236,221)
Plus: Additional shares available for issuance under the 2020 Equity Plan	1,600,000
Ending Balance, Equity securities available (shares)	1,699,314	646,480	904,437

Stockholders' Equity - Additi_2

Stockholders' Equity - Additional Awards Under 2011 LTIP (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Shares
Ending Balance (shares)	605,606
Restricted Stock, Restricted Stock Units, And Deferred Stock Units | 2011 Long Term Incentive Plan
Shares
Beginning Balance (shares)	419,426
Granted (shares)	603,171
Vested (shares)	(329,870)
Forfeited (shares)	(56,005)
Ending Balance (shares)	636,722
Weighted-Average Grant Date Fair Value per Share
Beginning (usd per share) | $ / shares	$ 14
Granted (usd per share) | $ / shares	11.94
Vested (usd per share) | $ / shares	14.05
Forfeited (usd per share) | $ / shares	12.49
Ending Balance (usd per share) | $ / shares	$ 12.16

Stockholders' Equity - ESPP Act

Stockholders' Equity - ESPP Activity (Details) - ESPP - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-Based Compensation Arrangement By Share-Based Payment Award, Shares Available [Roll Forward]
Beginning Balance, Equity securities available (shares)	184,860	208,159	228,279
Less: common stock purchased by eligible employees (shares)	(35,661)	(23,299)	(20,120)
Ending Balance, Equity securities available (shares)	149,199	184,860	208,159

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	$ 5,508	$ 3,643	$ 4,954
Performance-based RSUs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	2,019	1,434	2,127
Time-based RSUs and restricted stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	3,389	2,119	2,756
ESPP
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock based compensation	$ 100	$ 90	$ 71

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) Attributable to Current Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Loss before income taxes	$ (21,770)	$ (13,423)	$ (2,185)
Current:
Federal tax	0	0	0
State tax	58	582	838
Foreign tax	(150)	13	148
Total current	(92)	595	986
Deferred:
Federal tax	20,594	(2,121)	(1,467)
State tax	1,910	(1,239)	(532)
Foreign tax	43	107	307
Total deferred	22,547	(3,253)	(1,692)
(Provision for) benefit from income taxes	$ 22,455	$ (2,658)	$ (706)

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Loss before income taxes	$ (21,770)	$ (13,423)	$ (2,185)
Income taxes computed at the federal statutory rate	(4,572)	(2,819)	(459)
State income taxes, net of federal benefit	(703)	(567)	306
Goodwill impairment	6,341	2,243	0
Change in valuation allowance	22,108	0	0
Research and development and other tax credits	(1,316)	(1,790)	(1,144)
Excess executive compensation	266	322	281
Other	331	(47)	310
(Provision for) benefit from income taxes	$ 22,455	$ (2,658)	$ (706)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income taxes computed at the federal statutory rate	21.00%	21.00%	21.00%
State income taxes, net of federal benefit	3.20%	4.20%	(14.00%)
Goodwill impairment	(29.10%)	(16.70%)	0.00%
Change in valuation allowance	(101.60%)	0.00%	0.00%
Research and development and other tax credits	6.00%	13.30%	52.40%
Excess executive compensation	(1.20%)	(2.40%)	(12.90%)
Other	(1.50%)	0.40%	(14.20%)
(Provision for) benefit from income taxes	(103.10%)	19.80%	32.30%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Income Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Capitalized research and development costs	$ 13,367	$ 18,605
Net operating loss carryforward	18,081	15,978
Property and equipment	5,353	6,092
Accrued liabilities, reserves and other expenses	5,063	3,718
Research and development credits	5,533	4,140
Tax credits	717	1,467
Stock based compensation	1,917	1,600
Other	132	121
Gross deferred income tax assets	50,163	51,721
Deferred income tax liabilities:
Intangible assets	(2,015)	(2,430)
Prepaid and other expenses	(214)	(308)
Gross deferred income tax liabilities	(2,229)	(2,738)
Net deferred income tax assets	47,934	48,983
Valuation allowance	(22,108)	0
Total deferred income tax assets	$ 25,826	$ 48,983

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2020
Valuation Allowance [Line Items]
Tax credit	$ 1,316	$ 1,790	$ 1,144
NOLs available for future years	79,700
Valuation allowance	(22,108)	$ 0
CARES Act
Valuation Allowance [Line Items]
Deferral of payroll taxes, CARES Act	2,100
Tax credit	1,300
Alternative minimum tax credit , CARES Act				$ 1,300
Domestic Tax Authority
Valuation Allowance [Line Items]
NOLs available for future years	$ 70,600
Minimum | State jurisdiction
Valuation Allowance [Line Items]
Statute of limitations	3 years
Maximum | State jurisdiction
Valuation Allowance [Line Items]
Statute of limitations	4 years

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies [Line Items]
Rent expense	$ 17.3	$ 17.7
Rent expense			$ 17.5
Minimum
Commitments And Contingencies [Line Items]
LOC contract period requirement	1 year
Operating leases, term of contract	1 month
Maximum
Commitments And Contingencies [Line Items]
LOC contract period requirement	3 years
Operating leases, term of contract	5 years

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments (Details) $ in Thousands	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
2021	$ 5,273
2022	3,539
2023	2,395
2024	1,672
2025	1,050
Thereafter	2,816
Total	16,745
Office and transmitter buildings
Lessee, Lease, Description [Line Items]
2021	6,236
2022	4,541
2023	3,371
2024	1,879
2025	1,230
Thereafter	1,470
Total	$ 18,727

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Defined contribution plan, matching contribution	$ 1.6	$ 1.6	$ 1.6

Related Parties (Details)

Related Parties (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Rent expense	$ 17.3	$ 17.7
Director
Related Party Transaction [Line Items]
Rent expense	3.5	$ 3.6
Rent expense			$ 3.6
Revenue	$ 0.7

Selected Quarterly Financial _3

Selected Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 37,480	$ 37,693	$ 35,739	$ 37,267	$ 39,548	$ 39,453	$ 39,525	$ 41,764	$ 148,180	$ 160,289	$ 169,474
Operating income (loss)	(24,449)	2,732	3,159	(4,108)	(12,239)	(2,692)	(1,992)	1,115	(22,665)	(15,809)	(3,173)
Net income (loss)	$ (46,610)	$ 3,165	$ 3,759	$ (4,539)	$ (9,511)	$ (1,326)	$ (670)	$ 742	$ (44,225)	$ (10,765)	$ (1,479)
Basic net (loss) income per common share (usd per share)	$ (2.44)	$ 0.17	$ 0.20	$ (0.24)
Diluted (loss) income per common share (usd per share)	$ (2.44)	$ 0.16	$ 0.20	$ (0.24)
Basic and diluted net income (loss) per common share (usd per share)					$ (0.50)	$ (0.07)	$ (0.03)	$ 0.04	$ (2.32)	$ (0.56)	$ (0.08)
Goodwill impairment	$ 8,800				$ 25,000				$ 25,007	$ 8,849	$ 0
Valuation allowance	$ 22,108				$ 0				$ 22,108	$ 0

VALUATION AND QUALIFYING ACCO_2

VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for Doubtful Accounts, Service Credits and Other - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at the Beginning of the Period	$ 1,293	$ 1,705	$ 1,065
Charged to Operations	1,382	1,248	2,125
Write-offs	(1,006)	(1,660)	(1,485)
Balance at the End of the Period	$ 1,669	$ 1,293	$ 1,705