Revenue and Contract Costs	6 Months Ended
Jun. 30, 2018
Revenue From Contract With Customer [Abstract]
Revenue and Contract Costs	Note 6 – Revenue and Contract Costs Revenue Policy The Company adopted ASC 606 on January 1, 2018 using the modified retrospective approach, which applies to all contracts not complete as of the date of adoption. Under ASC 606, the Company recognizes revenue when a customer obtains control of promised goods or services, in an amount that reflects the consideration expected to be received in exchange for those goods or services. The Company follows the five step model prescribed under ASC 606: (i) identify contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligation. Revenues are presented net of any sales or value added taxes collected from customers and remitted to the government. The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration expected to be transferred to the customer is probable. The Company applies judgment in determining the customer’s ability and intention to pay for services expected to be transferred, which is based on factors including the customer’s payment history, management’s ability to mitigate exposure to credit risk (for example, requiring payment in advance of the transfer of goods or services, or the ability to stop transferring promised goods or services in the event a customer fails to pay consideration when due) and experience selling to similarly situated customers. Performance obligations within a contract are identified based on the goods and services promised to be transferred in the contract. When a contract includes more than one promised good or service, the Company must apply judgment to determine whether the promises represent multiple performance obligations or a single, combined performance obligation. This evaluation requires the Company to determine if the promises are both capable of being distinct, where the customer can benefit from the good or service on its own or together with other resources readily available, and are distinct within the context of the contract, where the transfer of goods or services is separately identifiable from other promises in the contract. When both criteria are met, each promised good or service is accounted for as a separate performance obligation. In cases where the promises are distinct, the Company is further required to evaluate if the promises are a series of goods and services that are substantially the same and have the same pattern of transfer to the customer (referred to as the “series” guidance). When the Company determines that promises meet the series guidance, they are accounted for as a single, combined performance obligation. The number of performance obligations in the Company’s arrangements is not different under ASC 606 than the number of separate units of accounting under pervious guidance, as discussed further below. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative basis according to their standalone selling prices. The Company continues to determine standalone selling price based on the price at which the performance obligation is sold separately. If the Company does not have a history of selling a performance obligation, management applies judgment to estimate the standalone selling price, taking into consideration available information, including market conditions, factors considered to set list price, pricing of similar products, and internal pricing objectives. The corresponding allocated revenues are recognized as the performance obligations are satisfied, as discussed below. Research services revenues Research services revenues consist primarily of memberships to Research, Connect, and Analytics products. The majority of the Research revenues are annual subscriptions to our research, including access to all or a designated portion of our research and, depending on the type of license, unlimited phone or email analyst inquiry and unlimited participation in Forrester webinars, all of which are delivered throughout the contract period. The Company has concluded that the promises represent a stand ready obligation to provide a daily information service, in which the services are the same each day, every day is distinct, and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these subscriptions meet the requirements of the series guidance and are each accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. Research revenues also include sales of electronic reprints, which are written research documents prepared by Forrester’s analysts and hosted via an on-line platform. Reprints include a promise to deliver a customer-selected research document and certain usage data provided through the on-line platform, which represents two performance obligations. The Company satisfies the performance obligation for the research document by providing access to the electronic reprint and accordingly recognizes revenue at that point in time. The Company satisfies the performance obligation for the data portion of the reprint on a daily basis and accordingly recognizes revenue over time. The majority of the Connect revenues are the Company’s Leadership Board product which includes access to the Research offering, access to a private forum with other Leadership Board member peers, access to a Forrester advisor, member-generated content, and one Event ticket. The Company has concluded that all promises, other than the Event ticket, represent a stand ready obligation to provide a daily information and peer service, in which the services are the same each day, every day is distinct, and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these promises meet the requirements of the series guidance and are accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. The Event ticket is accounted for as a separate performance obligation and is recognized when the Event occurs. Analytics revenues are annual subscriptions to access designated survey data products and typically include a data advisor, all of which are delivered throughout the contract period. For Analytics subscriptions, the Company has concluded that the promises represent a stand ready obligation to provide a daily data service, in which the services are the same each day, every day is distinct and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these subscriptions meet the requirements of the series guidance and are accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. Certain of the Analytics products include advisory services which are accounted for as a separate performance obligation and are recognized at the point in time the session is completed or the final deliverable is transferred to the customer. Advisory services and events revenues Advisory services and events revenues consists of sales of advisory services, consulting projects, and Events. Advisory services revenues are short-term presentations or knowledge sharing sessions (which can range from one hour to two days), such as workshops, speeches and advisory days. Each is a promise for a Forrester analyst to deliver a deeper understanding of Forrester’s published research and represents a single performance obligation. Revenue is recognized at the point in time the session is completed or the final deliverable is transferred to the customer. Consulting project revenues consists of the delivery of focused insights and recommendations that assist customers with their challenges in developing and executing strategies around technology, customer experience and digital transformation. Projects are fixed-fee arrangements that are generally completed within two weeks to three months. The Company concluded that each project represents a single performance obligation as they are a single promise to deliver a customized engagement and deliverable. For the majority of these services, either practically or contractually, the work performed and delivered to the customer has no alternative use to the Company. Additionally, Forrester maintains an enforceable right to payment at all times throughout the contract. The Company utilizes an input method and recognizes revenue over time, based on hours expended relative to the total estimated hours required to satisfy the performance obligation. This input method was chosen since it closely aligns with how control of interim deliverables is transferred to the customer throughout the engagement and is also the method used internally to price the project and assess operational performance. If the Company were to enter into an agreement where it does not have an enforceable right to payment at all times, revenue would be recognized at the point in time the project is completed. Events revenues consist of either ticket or sponsorship sales for a Forrester-hosted event. Each is a single promise that either allows entry to, or grants the right to promote a product or service at, a specific event. The Company concluded that each of these represents a single performance obligation. The Company recognizes revenue at the completion of the Event, which is the point in time when the customer has received the benefit(s) from attending or sponsoring the Event. Prepaid performance obligations, including Event tickets, reprints, advisory and consulting hours, on non-cancellable contracts that the Company estimates will expire unused are recognized in proportion to the pattern of related rights exercised by the customer. This assessment requires significant judgment, including estimating the percentage of prepaid rights that will go unexercised and anticipating the impact that future changes to products, pricing and customer engagement will have on actual expirations. The Company periodically updates the rates used to recognize unexercised rights. Refer to Note 10, Operating Segments, for a summary of disaggregated revenue by product category and business segment. Contract Modifications The Company considers a contract modification to exist when a mutually agreed upon change creates new, or updates existing, enforceable rights and obligations. ASC 606 introduced three specific methods to account for contract modifications depending on the nature of the change(s) in scope or price to the original contract. The new guidance is consistent with how the Company has historically accounted for contract modifications and as a result, will not have an impact on the Company’s results of operations. The majority of the Company’s contract modifications result in additional or remaining distinct goods and services, and are treated on a prospective basis. Under the prospective method, the transaction price is updated to combine the unrecognized amount as of the modification date plus the additional transaction price from the modification. This amount is then re-allocated to the remaining distinct performance obligations and recognized accordingly. Consulting services contracts can be modified to update the scope of the services purchased. Since a consulting project is a single performance obligation that is only partially satisfied at the modification date, the updated project requirements are not distinct and the modification is accounted for as part of the existing contract. The effect of the modification on the transaction price and the Company’s measure of progress for the performance obligation to which is relates, is recognized as an adjustment to revenue (either an increase or decrease) on a cumulative catch-up basis. For the three and six months ended June 30, 2018, the Company recorded an immaterial amount of cumulative catch-up adjustments. Accounts Receivable Accounts receivable includes amounts billed and currently due from customers. Since the only condition for payment of our invoices is the passage of time, the Company records a receivable on the date the invoice is issued. Also included in accounts receivable are unbilled amounts resulting from revenue exceeding the amount billed to the customer, where the right to payment is unconditional. If the right to payment for services performed was conditional on something other than the passage of time, the unbilled amount would be recorded as a separate contract asset. There were no contract assets as of June 30, 2018. The majority of the Company’s contracts are non-cancellable. However, for contracts that are cancellable by the customer, the Company does not record a receivable when it issues an invoice. The Company records accounts receivable on these contracts only up to the amount of revenue earned but not yet collected. In addition, since the majority of the Company’s contracts are for a duration of one year and payment is expected within one year from the transfer of goods and services, the Company does not adjust its receivables or transaction price for the effects of a significant financing component. Deferred Revenue The Company refers to contract liabilities as deferred revenue on the Consolidated Balance Sheets. Deferred revenue consists of billings in excess of revenue recognized. Similar to accounts receivable, the Company does not record deferred revenue for invoices issued on a cancellable contract. During the three and six months ended June 30, 2018, the Company recognized approximately $45.9 million and $103.9 million of revenue related to its deferred revenue balance at January 1, 2018. In order to determine revenue recognized in the current period from deferred revenue at the beginning of the period, the Company first allocates revenue to the individual deferred revenue balance outstanding at the beginning of the period, until the revenue equals that balance. Approximately $246.8 million of revenue is expected to be recognized during the next 12 to 24 months from remaining performance obligations as of June 30, 2018. Cost to Obtain and Fulfill Contracts The Company capitalizes commissions paid to internal sales representatives and related fringe benefits costs that are incremental to obtaining customer contracts. These costs are included in deferred commissions on the Consolidated Balance Sheets. The judgments made in determining the amount of costs incurred include the types of costs to capitalize and whether or not the costs are in fact incremental. The Company elected the practical expedient to account for these costs at a portfolio level as the Company’s contracts are similar in nature and the amortization model used closely matches the amortization expense that would be recognized on a contract-by-contract basis. Costs to obtain a contract are amortized to operations as the related revenue is recognized over the initial contract term. Amortization expense related to deferred commissions was $8.2 million and $15.2 million for the three and six months ended June 30, 2018, respectively. The Company evaluates the recoverability of deferred commissions at each balance sheet date. Costs to fulfill the Company’s contracts, such as our survey costs for our Analytics product line, do not meet the specified capitalization criteria as defined in the guidance and as such are expensed as incurred.

Note 6 – Revenue and Contract Costs

Revenue Policy

The Company adopted ASC 606 on January 1, 2018 using the modified retrospective approach, which applies to all contracts not complete as of the date of adoption. Under ASC 606, the Company recognizes revenue when a customer obtains control of promised goods or services, in an amount that reflects the consideration expected to be received in exchange for those goods or services. The Company follows the five step model prescribed under ASC 606: (i) identify contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligation. Revenues are presented net of any sales or value added taxes collected from customers and remitted to the government.

The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration expected to be transferred to the customer is probable. The Company applies judgment in determining the customer’s ability and intention to pay for services expected to be transferred, which is based on factors including the customer’s payment history, management’s ability to mitigate exposure to credit risk (for example, requiring payment in advance of the transfer of goods or services, or the ability to stop transferring promised goods or services in the event a customer fails to pay consideration when due) and experience selling to similarly situated customers.

Performance obligations within a contract are identified based on the goods and services promised to be transferred in the contract. When a contract includes more than one promised good or service, the Company must apply judgment to determine whether the promises represent multiple performance obligations or a single, combined performance obligation. This evaluation requires the Company to determine if the promises are both capable of being distinct, where the customer can benefit from the good or service on its own or together with other resources readily available, and are distinct within the context of the contract, where the transfer of goods or services is separately identifiable from other promises in the contract. When both criteria are met, each promised good or service is accounted for as a separate performance obligation. In cases where the promises are distinct, the Company is further required to evaluate if the promises are a series of goods and services that are substantially the same and have the same pattern of transfer to the customer (referred to as the “series” guidance). When the Company determines that promises meet the series guidance, they are accounted for as a single, combined performance obligation. The number of performance obligations in the Company’s arrangements is not different under ASC 606 than the number of separate units of accounting under pervious guidance, as discussed further below.

Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative basis according to their standalone selling prices. The Company continues to determine standalone selling price based on the price at which the performance obligation is sold separately. If the Company does not have a history of selling a performance obligation, management applies judgment to estimate the standalone selling price, taking into consideration available information, including market conditions, factors considered to set list price, pricing of similar products, and internal pricing objectives. The corresponding allocated revenues are recognized as the performance obligations are satisfied, as discussed below.

Research services revenues

Research services revenues consist primarily of memberships to Research, Connect, and Analytics products. The majority of the Research revenues are annual subscriptions to our research, including access to all or a designated portion of our research and, depending on the type of license, unlimited phone or email analyst inquiry and unlimited participation in Forrester webinars, all of which are delivered throughout the contract period. The Company has concluded that the promises represent a stand ready obligation to provide a daily information service, in which the services are the same each day, every day is distinct, and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these subscriptions meet the requirements of the series guidance and are each accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. Research revenues also include sales of electronic reprints, which are written research documents prepared by Forrester’s analysts and hosted via an on-line platform. Reprints include a promise to deliver a customer-selected research document and certain usage data provided through the on-line platform, which represents two performance obligations. The Company satisfies the performance obligation for the research document by providing access to the electronic reprint and accordingly recognizes revenue at that point in time. The Company satisfies the performance obligation for the data portion of the reprint on a daily basis and accordingly recognizes revenue over time.

The majority of the Connect revenues are the Company’s Leadership Board product which includes access to the Research offering, access to a private forum with other Leadership Board member peers, access to a Forrester advisor, member-generated content, and one Event ticket. The Company has concluded that all promises, other than the Event ticket, represent a stand ready obligation to provide a daily information and peer service, in which the services are the same each day, every day is distinct, and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these promises meet the requirements of the series guidance and are accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. The Event ticket is accounted for as a separate performance obligation and is recognized when the Event occurs.

Analytics revenues are annual subscriptions to access designated survey data products and typically include a data advisor, all of which are delivered throughout the contract period. For Analytics subscriptions, the Company has concluded that the promises represent a stand ready obligation to provide a daily data service, in which the services are the same each day, every day is distinct and the customer simultaneously receives and consumes the benefits as the Company transfers control throughout the contract period. Accordingly, these subscriptions meet the requirements of the series guidance and are accounted for as a single performance obligation. The Company recognizes revenue ratably over time, using an output measure of time elapsed. Certain of the Analytics products include advisory services which are accounted for as a separate performance obligation and are recognized at the point in time the session is completed or the final deliverable is transferred to the customer.

Advisory services and events revenues

Advisory services and events revenues consists of sales of advisory services, consulting projects, and Events.

Advisory services revenues are short-term presentations or knowledge sharing sessions (which can range from one hour to two days), such as workshops, speeches and advisory days. Each is a promise for a Forrester analyst to deliver a deeper understanding of Forrester’s published research and represents a single performance obligation. Revenue is recognized at the point in time the session is completed or the final deliverable is transferred to the customer.

Consulting project revenues consists of the delivery of focused insights and recommendations that assist customers with their challenges in developing and executing strategies around technology, customer experience and digital transformation. Projects are fixed-fee arrangements that are generally completed within two weeks to three months. The Company concluded that each project represents a single performance obligation as they are a single promise to deliver a customized engagement and deliverable. For the majority of these services, either practically or contractually, the work performed and delivered to the customer has no alternative use to the Company. Additionally, Forrester maintains an enforceable right to payment at all times throughout the contract. The Company utilizes an input method and recognizes revenue over time, based on hours expended relative to the total estimated hours required to satisfy the performance obligation. This input method was chosen since it closely aligns with how control of interim deliverables is transferred to the customer throughout the engagement and is also the method used internally to price the project and assess operational performance. If the Company were to enter into an agreement where it does not have an enforceable right to payment at all times, revenue would be recognized at the point in time the project is completed.

Events revenues consist of either ticket or sponsorship sales for a Forrester-hosted event. Each is a single promise that either allows entry to, or grants the right to promote a product or service at, a specific event. The Company concluded that each of these represents a single performance obligation. The Company recognizes revenue at the completion of the Event, which is the point in time when the customer has received the benefit(s) from attending or sponsoring the Event.

Prepaid performance obligations, including Event tickets, reprints, advisory and consulting hours, on non-cancellable contracts that the Company estimates will expire unused are recognized in proportion to the pattern of related rights exercised by the customer. This assessment requires significant judgment, including estimating the percentage of prepaid rights that will go unexercised and anticipating the impact that future changes to products, pricing and customer engagement will have on actual expirations. The Company periodically updates the rates used to recognize unexercised rights.

Refer to Note 10, Operating Segments, for a summary of disaggregated revenue by product category and business segment.

Contract Modifications

The Company considers a contract modification to exist when a mutually agreed upon change creates new, or updates existing, enforceable rights and obligations. ASC 606 introduced three specific methods to account for contract modifications depending on the nature of the change(s) in scope or price to the original contract. The new guidance is consistent with how the Company has historically accounted for contract modifications and as a result, will not have an impact on the Company’s results of operations.

The majority of the Company’s contract modifications result in additional or remaining distinct goods and services, and are treated on a prospective basis. Under the prospective method, the transaction price is updated to combine the unrecognized amount as of the modification date plus the additional transaction price from the modification. This amount is then re-allocated to the remaining distinct performance obligations and recognized accordingly.

Consulting services contracts can be modified to update the scope of the services purchased. Since a consulting project is a single performance obligation that is only partially satisfied at the modification date, the updated project requirements are not distinct and the modification is accounted for as part of the existing contract. The effect of the modification on the transaction price and the Company’s measure of progress for the performance obligation to which is relates, is recognized as an adjustment to revenue (either an increase or decrease) on a cumulative catch-up basis. For the three and six months ended June 30, 2018, the Company recorded an immaterial amount of cumulative catch-up adjustments.

Accounts Receivable

Accounts receivable includes amounts billed and currently due from customers. Since the only condition for payment of our invoices is the passage of time, the Company records a receivable on the date the invoice is issued. Also included in accounts receivable are unbilled amounts resulting from revenue exceeding the amount billed to the customer, where the right to payment is unconditional. If the right to payment for services performed was conditional on something other than the passage of time, the unbilled amount would be recorded as a separate contract asset. There were no contract assets as of June 30, 2018.

The majority of the Company’s contracts are non-cancellable. However, for contracts that are cancellable by the customer, the Company does not record a receivable when it issues an invoice. The Company records accounts receivable on these contracts only up to the amount of revenue earned but not yet collected.

In addition, since the majority of the Company’s contracts are for a duration of one year and payment is expected within one year from the transfer of goods and services, the Company does not adjust its receivables or transaction price for the effects of a significant financing component.

Deferred Revenue

The Company refers to contract liabilities as deferred revenue on the Consolidated Balance Sheets. Deferred revenue consists of billings in excess of revenue recognized. Similar to accounts receivable, the Company does not record deferred revenue for invoices issued on a cancellable contract.

During the three and six months ended June 30, 2018, the Company recognized approximately $45.9 million and $103.9 million of revenue related to its deferred revenue balance at January 1, 2018. In order to determine revenue recognized in the current period from deferred revenue at the beginning of the period, the Company first allocates revenue to the individual deferred revenue balance outstanding at the beginning of the period, until the revenue equals that balance.

Approximately $246.8 million of revenue is expected to be recognized during the next 12 to 24 months from remaining performance obligations as of June 30, 2018.

Cost to Obtain and Fulfill Contracts

The Company capitalizes commissions paid to internal sales representatives and related fringe benefits costs that are incremental to obtaining customer contracts. These costs are included in deferred commissions on the Consolidated Balance Sheets. The judgments made in determining the amount of costs incurred include the types of costs to capitalize and whether or not the costs are in fact incremental. The Company elected the practical expedient to account for these costs at a portfolio level as the Company’s contracts are similar in nature and the amortization model used closely matches the amortization expense that would be recognized on a contract-by-contract basis. Costs to obtain a contract are amortized to operations as the related revenue is recognized over the initial contract term. Amortization expense related to deferred commissions was $8.2 million and $15.2 million for the three and six months ended June 30, 2018, respectively. The Company evaluates the recoverability of deferred commissions at each balance sheet date.

Costs to fulfill the Company’s contracts, such as our survey costs for our Analytics product line, do not meet the specified capitalization criteria as defined in the guidance and as such are expensed as incurred.