General and Basis of Presentation (Policies)	9 Months Ended
Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation, Policy	The accompanying unaudited condensed consolidated financial statements include the accounts of Telos and its wholly-owned subsidiaries. All intercompany transactions have been eliminated in consolidation.
Basis of Accounting, Policy	The accompanying condensed consolidated financial statements for the three and nine months ended September 30, 2021 and 2020 have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to rules and regulations of the Securities and Exchange Commission (“SEC”).
Segment Reporting	Operating segments are defined as components of an enterprise for which separate financial information is available and evaluated regularly by the chief operating decision maker (“CODM”), or decision making group, in deciding how to allocate resources and assess performance. We currently operate in one operating and reportable business segment for financial reporting purposes. Our Chief Executive Officer is the CODM. The CODM evaluates profitability based on consolidated results.
Recent Accounting Pronouncements	Accounting Standards Recently Adopted In December 2019, the Financial Accounting Standard Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2019-12, “Simplifying the Accounting for Income Taxes (Topic 740)”, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The ASU also clarifies and amends existing guidance to improve consistent application. This standard is effective for reporting periods beginning after December 15, 2020, which made this standard effective for us on January 1, 2021. The adoption of this ASU did not have a material impact on our condensed consolidated financial position, results of operations and cash flows.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value, where cost is determined using the weighted average method. Substantially all inventories consist of purchased off-the-shelf hardware and software, and component computer parts used in connection with system integration services that we perform. An allowance for obsolete, slow-moving or nonsaleable inventory is provided for all other inventories. This allowance is based on our overall obsolescence experience and our assessment of future inventory requirements. This charge is taken primarily due to the age of the specific inventory and the significant additional costs that would be necessary to upgrade to current standards as well as the lack of forecasted sales for such inventory in the near future. Gross inventory was $2.9 million and $4.2 million as of September 30, 2021 and December 31, 2020, respectively. As of September 30, 2021, it is management’s judgment that we have fully provided for any potential inventory obsolescence, which was $0.8 million and $0.9 million as of September 30, 2021 and December 31, 2020, respectively.
Software Development Costs	Software Development Costs We account for development costs of our software to be sold in accordance with ASC Topic 985-20, “Software – Costs of Software to be Sold, Leased, or Marketed” and for internal use software in accordance with ASC Topic 350-40 “Internal Use Software”. Under both standards, software development costs are expensed as incurred until technological feasibility is reached, at which time additional costs are capitalized until the product is available for general release to customers or is ready for its intended use, as appropriate. Technological feasibility is established when all planning, designing, coding and testing activities have been completed, and all risks have been identified. Software development costs are capitalized and amortized over the estimated product life of 2 years on a straight-line basis, which are included as a part of intangible assets. The Company analyzes the net realizable value of capitalized software development costs on at least an annual basis and has determined that there is no indication of impairment of the capitalized software development costs as forecasted future sales are adequate to support the carrying values.
Income Taxes	Income Taxes We account for income taxes in accordance with ASC 740, “Income Taxes”. Under ASC 740, deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences and income tax credits. Deferred tax assets and liabilities are measured by applying enacted statutory tax rates that are applicable to the future years in which deferred tax assets or liabilities are expected to be settled or realized for differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. Any change in tax rates on deferred tax assets and liabilities is recognized in net income in the period in which the tax rate change is enacted. We follow the provisions of ASC 740 related to accounting for uncertainty in income taxes. The accounting estimates related to liabilities for uncertain tax positions require us to make judgments regarding the sustainability of each uncertain tax position based on its technical merits. If we determine it is more likely than not that a tax position will be sustained based on its technical merits, we record the impact of the position in our condensed consolidated financial statements at the largest amount that is greater than fifty percent likely of being realized upon ultimate settlement. These estimates are updated at each reporting date based on the facts, circumstances and information available. We are also required to assess at each reporting date whether it is reasonably possible that any significant increases or decreases to our unrecognized tax benefits will occur during the next 12 months.
Goodwill	Goodwill Goodwill is recorded as the difference between the aggregate consideration paid for an acquisition and the fair value of net tangible and intangible assets acquired and liabilities assumed. Goodwill is not amortized, but rather tested for potential impairment annually during our fourth quarter, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Such circumstances could include, but are not limited to: (1) a significant adverse change in legal factors or business climate, or (2) a loss of key contracts or customers. The goodwill impairment test is performed at the reporting unit level. The Company estimates and compares the fair value of each reporting unit to its respective carrying value including goodwill. If the fair value is less than the carrying value, the amount of impairment expense is equal to the difference between the reporting unit’s fair value and the reporting unit’s carrying value. Goodwill is amortized and deducted over a 15-year period for tax purposes.
Stock-Based Compensation	Stock-Based Compensation Under our 2016 Omnibus Long-Term Incentive Plan, as amended (the “2016 LTIP”), we have the ability to award restricted stock units with time-based vesting (“Service-Based RSUs”), and restricted stock units with performance-based vesting (“Performance-Based RSUs”) to senior executives, directors, employees and other eligible service providers. Under the 2016 LTIP, our Board of Directors or, by designation of authority, the Compensation Committee of our Board of Directors has the discretion to establish the terms, conditions and criteria of the various awards, including the weighing and vesting schedule of Service-Based RSUs and the performance conditions applicable to the Performance-Based RSUs, including the achievement of certain financial performance criteria or price targets for our common stock. Upon vesting, Service-Based RSUs and Performance-Based RSUs will be settled in the Company’s common stock. •Service-Based RSUs granted to eligible employees as an incentive generally vest in equal installments over two to three years from the date of grant. Service-Based RSUs granted to senior executives in 2021 vest in three annual installments from the date of grant, with 30% vesting on the first and second anniversaries and 40% vesting on the third anniversary. The grant date fair value per share is equal to the closing stock price on the date of grant. •Performance-Based RSUs may vest upon the achievement of a defined performance target or at the end of the defined performance period from the date of grant, whichever initially occurs. The grant date fair value per share of these Performance-Based RSUs is equal to the closing stock price on the date of the grant or the fair value of the award on the grant date as determined through an independent valuation, for performance-based RSUs with market condition. Performance-Based RSUs may vest upon the achievement of certain price targets for the Company’s common stock anytime over a three-year period from the date of grant. In order to reflect the substantive characteristics of these market condition awards, the Company employs a Monte Carlo simulation valuation model to calculate the grant date fair value and corresponding requisite service period of the award. Monte Carlo approaches are a class of computational algorithms that rely on repeated random sampling to compute their results. This approach allows the calculation of the value of such awards based on a large number of possible stock price path scenarios. We recognize these share-based payment transactions when services from the employees are received and recognize a corresponding increase in additional paid-in capital in our condensed consolidated balance sheets. The measurement objective for these equity awards is the estimated fair value at the date of grant of the equity instruments that we are obligated to issue when employees have rendered the requisite service and satisfied any other conditions necessary to earn the right to benefit from the instruments. The compensation expense for an award is recognized ratably over the requisite service period for the entire award, which is the period during which an employee is required to provide service in exchange for an award. Compensation expense for awards with performance conditions is recognized over the requisite service period if it is probable that the performance condition will be satisfied. If such performance conditions are not or are no longer considered probable, no compensation expense for these awards is recognized, and any previously recognized expense is reversed. If the performance condition is achieved prior to the completion of the requisite service period, any unrecognized compensation expense will be recognized in the period the performance condition is achieved. Compensation expense for awards with market conditions is recognized over the derived service period, or sooner, if the market condition is achieved. Previously recognized expense for awards with market conditions will never be reversed even if the market conditions is never achieved. We recognize forfeitures of share-based compensation awards as they occur. Share-based compensation expense is recognized as part of cost of sales and general and administrative expenses in our condensed consolidated statements of operations.
Net Loss per Share	Net Loss per ShareBasic net earnings (loss) per share is computed by dividing the net earnings (loss) by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net earnings (loss) per share is computed by dividing the net earnings (loss) by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of unvested restricted stock, unvested restricted stock units and common stock warrants.
Other Comprehensive Loss	Other Comprehensive Loss Our functional currency is the U.S. Dollar. For one of our wholly owned subsidiaries, the functional currency is the local currency. For this subsidiary, the translation of its foreign currency into U.S. Dollars is performed for assets and liabilities using current foreign currency exchange rates in effect at the balance sheet date and for revenue and expense accounts using average foreign currency exchange rates during the periods presented. Translation gains and losses are included in stockholders’ equity (deficit) as a component of accumulated other comprehensive income (loss).
Revenue Recognition	Performance Obligation We account for revenue in accordance with ASC Topic 606, “Revenue from Contracts with Customers”. The unit of account in ASC 606 is a performance obligation, which is a promise in a contract with a customer to transfer a good or service to the customer. Timing of the satisfaction of performance obligations varies across our businesses due to our diverse product and service mix, customer base, and contractual terms. Significant judgment can be required in determining certain performance obligations, and these determinations could change the amount of revenue and profit recorded in a given period. Our contracts may have a single performance obligation or multiple performance obligations. When there are multiple performance obligations within a contract, we allocate the transaction price to each performance obligation based on our best estimate of standalone selling price. Contracts are routinely and often modified to account for changes in contract requirements, specifications, quantities, or price. Depending on the nature of the modification, we determine whether to account for the modification as an adjustment to the existing contract or as a new contract. Generally, modifications are not distinct from the existing contract due to the significant interrelatedness of the performance obligations and are therefore accounted for as an adjustment to the existing contract, and recognized as a cumulative adjustment to revenue (as either an increase or reduction of revenue) based on the modification’s effect on progress toward completion of a performance obligation. The majority of our revenue is recognized over time, as control is transferred continuously to our customers who receive and consume benefits as we perform, and is classified as services revenue. Revenue transferred to customers over time accounted for 91% and 92% of our revenue for the three and nine months ended September 30, 2021, and 93% and 92% of our revenue for the three and nine months ended September 30, 2020. All of our business groups earn services revenue under a variety of contract types, including time and materials, firm-fixed-price, firm-fixed-price level of effort, and cost plus fixed fee contract types, which may include variable consideration as discussed further below. Revenue is recognized over time using costs incurred to date relative to total estimated costs at completion to measure progress toward satisfying our performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, subcontractor costs and indirect expenses. Revenue that is recognized at a point in time is for the sale of software licenses in our Information Assurance / Xacta® and Secure Communications business groups and for the sale of resold products in Telos ID and Secure Networks, and is classified as product revenue. Revenue transferred to customers at a point in time accounted for 9% and 8% of our revenue for the three and nine months ended September 30, 2021 and 7% and 8% of our revenue for the three and nine months ended September 30, 2020. Revenue on these contracts is recognized when the customer obtains control of the transferred product or service, which is generally upon delivery of the product to the customer for their use, due to us maintaining control of the product until that point. Orders for the sale of software licenses may contain multiple performance obligations, such as maintenance, training, or consulting services, which are typically delivered over time, consistent with the transfer of control disclosed above for the provision of services. When an order contains multiple performance obligations, we allocate the transaction price to the performance obligations using our best estimate of standalone selling price. Contract Estimates Due to the transfer of control over time, revenue is recognized based on progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the performance obligations. We generally use the cost-to-cost measure of progress on a proportional performance basis for our contracts because it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenues are recorded proportionally as costs are incurred. Due to the nature of the work required to be performed on certain of our performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. Contract estimates are based on various assumptions including labor and subcontractor costs, materials and other direct costs and the complexity of the work to be performed. A significant change in one or more of these estimates could affect the profitability of our contracts. We review and update our contract-related estimates regularly and recognize adjustments in estimated profit on contracts on a cumulative catch-up basis, which may result in an adjustment increasing or decreasing revenue to date on a contract in a particular period that the adjustment is identified. Revenue and profit in future periods of contract performance are recognized using the adjusted estimate. Our contracts may include various types of variable consideration, such as claims (for instance, indirect rate or other equitable adjustments) or incentive fees. We include estimated amounts in the transaction price based on all of the information available to us, including historical information and future estimations, and to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when any uncertainty associated with the variable consideration is resolved. Historically, most of our contracts do not include award or incentive fees. For incentive fees, we would include such fees in the transaction price to the extent we could reasonably estimate the amount of the fee. With limited historical experience, we have not included any revenue related to incentive fees in our estimated transaction prices. We may include in our contract estimates additional revenue for submitted contract modifications or claims against the customer when we believe we have an enforceable right to the modification or claim, the amount can be estimated reliably and its realization is probable. We consider the contractual/legal basis for the claim (in particular the FAR provisions), the facts and circumstances around any additional costs incurred, the reasonableness of those costs and the objective evidence available to support such claims. For our contracts that have an original duration of one year or less, we use the practical expedient applicable to such contracts and do not consider the time value of money. We capitalize sales commissions related to proprietary software and related services that are directly tied to sales. We do not elect the practical expedient to expense as incurred the incremental costs of obtaining a contract if the amortization period would have been one year or less. For the sales commissions that are capitalized, we amortize the asset over the expected customer life, which is based on recent and historical data. We have one reportable segment in accordance with ASC 280, Segment Reporting, as such, the disaggregation of revenue below reconciles directly to its unique reportable segment. We treat sales to U.S. customers as sales within the U.S. regardless of where the services are performed. Substantially all of our revenues are from U.S. customers as revenue derived from international customers is not currently meaningful. Contract Balances Contract assets are amounts that are invoiced as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Generally, revenue recognition occurs before billing, resulting in contract assets. These contract assets are referred to as unbilled receivables and are reported within accounts receivable, net of reserve on our condensed consolidated balance sheets. Billed receivables are amounts billed and due from our customers and are reported within accounts receivable, net of reserve on the condensed consolidated balance sheets. The portion of the payments retained by the customer until final contract settlement is not considered a significant financing component due to the intent of the retainage being the customer’s protection with respect to full and final performance under the contract. Contract liabilities are payments received in advance and milestone payments from our customers on selected contracts that exceed revenue earned to date, resulting in contract liabilities. Contract liabilities typically are not considered a significant financing component because they are generally satisfied within one year and are used to meet working capital demands that can be higher in the early stages of a contract. Contract liabilities are reported on our condensed consolidated balance sheets on a net contract basis at the end of each reporting period. As of September 30, 2021 and December 31, 2020, the contract liabilities primarily related to product support services.

General and Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying unaudited condensed consolidated financial statements include the accounts of Telos and its wholly-owned subsidiaries. All intercompany transactions have been eliminated in consolidation.

Basis of Accounting, Policy

The accompanying condensed consolidated financial statements for the three and nine months ended September 30, 2021 and 2020 have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to rules and regulations of the Securities and Exchange Commission (“SEC”).

Segment Reporting

Operating segments are defined as components of an enterprise for which separate financial information is available and evaluated regularly by the chief operating decision maker (“CODM”), or decision making group, in deciding how to allocate resources and assess performance. We currently operate in one operating and reportable business segment for financial reporting purposes. Our Chief Executive Officer is the CODM. The CODM evaluates profitability based on consolidated results.

Recent Accounting Pronouncements

Accounting Standards Recently Adopted

In December 2019, the Financial Accounting Standard Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2019-12, “Simplifying the Accounting for Income Taxes (Topic 740)”, which simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The ASU also clarifies and amends existing guidance to improve consistent application. This standard is effective for reporting periods beginning after December 15, 2020, which made this standard effective for us on January 1, 2021. The adoption of this ASU did not have a material impact on our condensed consolidated financial position, results of operations and cash flows.

Inventories

Inventories are stated at the lower of cost or net realizable value, where cost is determined using the weighted average method. Substantially all inventories consist of purchased off-the-shelf hardware and software, and component computer parts used in connection with system integration services that we perform. An allowance for obsolete, slow-moving or nonsaleable inventory is provided for all other inventories. This allowance is based on our overall obsolescence experience and our assessment of future inventory requirements. This charge is taken primarily due to the age of the specific inventory and the significant additional costs that would be necessary to upgrade to current standards as well as the lack of forecasted sales for such inventory in the near future. Gross inventory was $2.9 million and $4.2 million as of September 30, 2021 and December 31, 2020, respectively. As of September 30, 2021, it is management’s judgment that we have fully provided for any potential inventory obsolescence, which was $0.8 million and $0.9 million as of September 30, 2021 and December 31, 2020, respectively.

Software Development Costs

We account for development costs of our software to be sold in accordance with ASC Topic 985-20, “Software – Costs of Software to be Sold, Leased, or Marketed” and for internal use software in accordance with ASC Topic 350-40 “Internal Use Software”. Under both standards, software development costs are expensed as incurred until technological feasibility is reached, at which time additional costs are capitalized until the product is available for general release to customers or is ready for its intended use, as appropriate. Technological feasibility is established when all planning, designing, coding and testing activities have been completed, and all risks have been identified. Software development costs are capitalized and amortized over the estimated product life of 2 years on a straight-line basis, which are included as a part of intangible assets. The Company analyzes the net realizable value of capitalized software development costs on at least an annual basis and has determined that there is no indication of impairment of the capitalized software development costs as forecasted future sales are adequate to support the carrying values.

Income Taxes

We account for income taxes in accordance with ASC 740, “Income Taxes”. Under ASC 740, deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences and income tax credits. Deferred tax assets and liabilities are measured by applying enacted statutory tax rates that are applicable to the future years in which deferred tax assets or liabilities are expected to be settled or realized for differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. Any change in tax rates on deferred tax assets and liabilities is recognized in net income in the period in which the tax rate change is enacted.

We follow the provisions of ASC 740 related to accounting for uncertainty in income taxes. The accounting estimates related to liabilities for uncertain tax positions require us to make judgments regarding the sustainability of each uncertain tax position based on its technical merits. If we determine it is more likely than not that a tax position will be sustained based on its technical merits, we record the impact of the position in our condensed consolidated financial statements at the largest amount that is greater than fifty percent likely of being realized upon ultimate settlement. These estimates are updated at each reporting date based on the facts, circumstances and information available. We are also required to assess at each reporting date whether it is reasonably possible that any significant increases or decreases to our unrecognized tax benefits will occur during the next 12 months.

Goodwill

Goodwill is recorded as the difference between the aggregate consideration paid for an acquisition and the fair value of net tangible and intangible assets acquired and liabilities assumed. Goodwill is not amortized, but rather tested for potential impairment annually during our fourth quarter, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Such circumstances could include, but are not limited to: (1) a significant adverse change in legal factors or business climate, or (2) a loss of key contracts or customers.

The goodwill impairment test is performed at the reporting unit level. The Company estimates and compares the fair value of each reporting unit to its respective carrying value including goodwill. If the fair value is less than the carrying value, the amount of impairment expense is equal to the difference between the reporting unit’s fair value and the reporting unit’s carrying value.

Goodwill is amortized and deducted over a 15-year period for tax purposes.

Stock-Based Compensation

Under our 2016 Omnibus Long-Term Incentive Plan, as amended (the “2016 LTIP”), we have the ability to award restricted stock units with time-based vesting (“Service-Based RSUs”), and restricted stock units with performance-based vesting (“Performance-Based RSUs”) to senior executives, directors, employees and other eligible service providers. Under the 2016 LTIP, our Board of Directors or, by designation of authority, the Compensation Committee of our Board of Directors has the discretion to establish the terms, conditions and criteria of the various awards, including the weighing and vesting schedule of Service-Based RSUs and the performance conditions applicable to the Performance-Based RSUs, including the achievement of certain financial performance criteria or price targets for our common stock. Upon vesting, Service-Based RSUs and Performance-Based RSUs will be settled in the Company’s common stock.

•Service-Based RSUs granted to eligible employees as an incentive generally vest in equal installments over two to three years from the date of grant. Service-Based RSUs granted to senior executives in 2021 vest in three annual installments from the date of grant, with 30% vesting on the first and second anniversaries and 40% vesting on the third anniversary. The grant date fair value per share is equal to the closing stock price on the date of grant.

•Performance-Based RSUs may vest upon the achievement of a defined performance target or at the end of the defined performance period from the date of grant, whichever initially occurs. The grant date fair value per share of these Performance-Based RSUs is equal to the closing stock price on the date of the grant or the fair value of the award on the grant date as determined through an independent valuation, for performance-based RSUs with market condition. Performance-Based RSUs may vest upon the achievement of certain price targets for the Company’s common stock anytime over a three-year period from the date of grant. In order to reflect the substantive characteristics of these market condition awards, the Company employs a Monte Carlo simulation valuation model to calculate the grant date fair value and corresponding requisite service period of the award. Monte Carlo approaches are a class of computational algorithms that rely on repeated random sampling to compute their results. This approach allows the calculation of the value of such awards based on a large number of possible stock price path scenarios.

We recognize these share-based payment transactions when services from the employees are received and recognize a corresponding increase in additional paid-in capital in our condensed consolidated balance sheets. The measurement objective for these equity awards is the estimated fair value at the date of grant of the equity instruments that we are obligated to issue when employees have rendered the requisite service and satisfied any other conditions necessary to earn the right to benefit from the instruments. The compensation expense for an award is recognized ratably over the requisite service period for the entire award, which is the period during which an employee is required to provide service in exchange for an award. Compensation expense for awards with performance conditions is recognized over the requisite service period if it is probable that the performance condition will be satisfied. If such performance conditions are not or are no longer considered probable, no compensation expense for these awards is recognized, and any previously recognized expense is reversed. If the performance condition is achieved prior to the completion of the requisite service period, any unrecognized compensation expense will be recognized in the period the performance condition is achieved. Compensation expense for awards with market conditions is recognized over the derived service period, or sooner, if the market condition is achieved. Previously recognized expense for awards with market conditions will never be reversed even if the market conditions is never achieved. We recognize forfeitures of share-based compensation awards as they occur. Share-based compensation expense is recognized as part of cost of sales and general and administrative expenses in our condensed consolidated statements of operations.

Net Loss per Share

Net Loss per ShareBasic net earnings (loss) per share is computed by dividing the net earnings (loss) by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net earnings (loss) per share is computed by dividing the net earnings (loss) by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of unvested restricted stock, unvested restricted stock units and common stock warrants.

Other Comprehensive Loss

Our functional currency is the U.S. Dollar. For one of our wholly owned subsidiaries, the functional currency is the local currency. For this subsidiary, the translation of its foreign currency into U.S. Dollars is performed for assets and liabilities using current foreign currency exchange rates in effect at the balance sheet date and for revenue and expense accounts using average foreign currency exchange rates during the periods presented. Translation gains and losses are included in stockholders’ equity (deficit) as a component of accumulated other comprehensive income (loss).

Revenue Recognition

Performance Obligation

We account for revenue in accordance with ASC Topic 606, “Revenue from Contracts with Customers”. The unit of account in ASC 606 is a performance obligation, which is a promise in a contract with a customer to transfer a good or service to the customer. Timing of the satisfaction of performance obligations varies across our businesses due to our diverse product and service mix, customer base, and contractual terms. Significant judgment can be required in determining certain performance obligations, and these determinations could change the amount of revenue and profit recorded in a given period. Our contracts may have a single performance obligation or multiple performance obligations. When there are multiple performance obligations within a contract, we allocate the transaction price to each performance obligation based on our best estimate of standalone selling price.

Contracts are routinely and often modified to account for changes in contract requirements, specifications, quantities, or price. Depending on the nature of the modification, we determine whether to account for the modification as an adjustment to the existing contract or as a new contract. Generally, modifications are not distinct from the existing contract due to the significant interrelatedness of the performance obligations and are therefore accounted for as an adjustment to the existing contract, and recognized as a cumulative adjustment to revenue (as either an increase or reduction of revenue) based on the modification’s effect on progress toward completion of a performance obligation.

The majority of our revenue is recognized over time, as control is transferred continuously to our customers who receive and consume benefits as we perform, and is classified as services revenue. Revenue transferred to customers over time accounted for 91% and 92% of our revenue for the three and nine months ended September 30, 2021, and 93% and 92% of our revenue for the three and nine months ended September 30, 2020. All of our business groups earn services revenue under a variety of contract types, including time and materials, firm-fixed-price, firm-fixed-price level of effort, and cost plus fixed fee contract types, which may include variable consideration as discussed further below. Revenue is recognized over time using costs incurred to date relative to total estimated costs at completion to measure progress toward satisfying our performance obligations. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Contract costs include labor, material, subcontractor costs and indirect expenses.

Revenue that is recognized at a point in time is for the sale of software licenses in our Information Assurance / Xacta® and Secure Communications business groups and for the sale of resold products in Telos ID and Secure Networks, and is classified as product revenue. Revenue transferred to customers at a point in time accounted for 9% and 8% of our revenue for the three and nine months ended September 30, 2021 and 7% and 8% of our revenue for the three and nine months ended September 30, 2020. Revenue on these contracts is recognized when the customer obtains control of the transferred product or service, which is generally upon delivery of the product to the customer for their use, due to us maintaining control of the product until that point. Orders for the sale of software licenses may contain multiple performance obligations, such as maintenance, training, or consulting services, which are typically delivered over time, consistent with the transfer of control disclosed above for the provision of services. When an order contains multiple performance obligations, we allocate the transaction price to the performance obligations using our best estimate of standalone selling price.

Contract Estimates

Due to the transfer of control over time, revenue is recognized based on progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the performance obligations. We generally use the cost-to-cost measure of progress on a proportional performance basis for our contracts because it best depicts the transfer of control to the customer which occurs as we incur costs on our contracts. Under the cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date to the total estimated costs at completion of the performance obligation. Revenues are recorded proportionally as costs are incurred. Due to the nature of the work required to be performed on certain of our performance obligations, the estimation of total revenue and cost at completion is complex, subject to many variables and requires significant judgment. Contract estimates are based on various assumptions including labor and subcontractor costs, materials and other direct costs and the complexity of the work to be performed. A significant change in one or more of these estimates could affect the profitability of our contracts. We review and update our contract-related estimates regularly and recognize adjustments in estimated profit on contracts on a cumulative catch-up basis, which may result in an adjustment increasing or decreasing revenue to date on a contract in a particular period that the adjustment is identified. Revenue and profit in future periods of contract performance are recognized using the adjusted estimate.

Our contracts may include various types of variable consideration, such as claims (for instance, indirect rate or other equitable adjustments) or incentive fees. We include estimated amounts in the transaction price based on all of the information available to us, including historical information and future estimations, and to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when any uncertainty associated with the variable consideration is resolved.

Historically, most of our contracts do not include award or incentive fees. For incentive fees, we would include such fees in the transaction price to the extent we could reasonably estimate the amount of the fee. With limited historical experience, we have not included any revenue related to incentive fees in our estimated transaction prices. We may include in our contract estimates additional revenue for submitted contract modifications or claims against the customer when we believe we have an enforceable right to the modification or claim, the amount can be estimated reliably and its realization is probable. We consider the contractual/legal basis for the claim (in particular the FAR provisions), the facts and circumstances around any additional costs incurred, the reasonableness of those costs and the objective evidence available to support such claims.

For our contracts that have an original duration of one year or less, we use the practical expedient applicable to such contracts and do not consider the time value of money. We capitalize sales commissions related to proprietary software and related services that are directly tied to sales. We do not elect the practical expedient to expense as incurred the incremental costs of obtaining a contract if the amortization period would have been one year or less. For the sales commissions that are capitalized, we amortize the asset over the expected customer life, which is based on recent and historical data.

We have one reportable segment in accordance with ASC 280, Segment Reporting, as such, the disaggregation of revenue below reconciles directly to its unique reportable segment. We treat sales to U.S. customers as sales within the U.S. regardless of where the services are performed. Substantially all of our revenues are from U.S. customers as revenue derived from international customers is not currently meaningful.

Contract Balances

Contract assets are amounts that are invoiced as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals or upon achievement of contractual milestones. Generally, revenue recognition occurs before billing, resulting in contract assets. These contract assets are referred to as unbilled receivables and are reported within accounts receivable, net of reserve on our condensed consolidated balance sheets.

Billed receivables are amounts billed and due from our customers and are reported within accounts receivable, net of reserve on the condensed consolidated balance sheets. The portion of the payments retained by the customer until final contract settlement is not considered a significant financing component due to the intent of the retainage being the customer’s protection with respect to full and final performance under the contract.

Contract liabilities are payments received in advance and milestone payments from our customers on selected contracts that exceed revenue earned to date, resulting in contract liabilities. Contract liabilities typically are not considered a significant financing component because they are generally satisfied within one year and are used to meet working capital demands that can be higher in the early stages of a contract. Contract liabilities are reported on our condensed consolidated balance sheets on a net contract basis at the end of each reporting period. As of September 30, 2021 and December 31, 2020, the contract liabilities primarily related to product support services.