Forrester Research (FORR) 10-K 9 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 05, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	FORR
Entity Registrant Name	FORRESTER RESEARCH, INC.
Entity Central Index Key	1,023,313
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		18,040,000
Entity Public Float			$ 377,000,000

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 79,790	$ 76,958
Marketable investments (Note 3)	54,333	61,147
Accounts receivable, net (Note 11)	70,023	58,812
Deferred commissions	13,731	12,052
Prepaid expenses and other current assets	18,942	14,467
Total current assets	236,819	223,436
Property and equipment, net (Note 11)	25,249	23,894
Goodwill (Note 2)	76,169	73,193
Intangible assets, net (Note 2)	732	1,464
Other assets	6,231	13,798
Total assets	345,200	335,785
Current Liabilities:
Accounts payable	217	1,806
Accrued expenses and other current liabilities (Note 11)	49,629	41,403
Deferred revenue	145,207	134,265
Total current liabilities	195,053	177,474
Non-current liabilities	8,958	8,275
Total liabilities	204,011	185,749
Commitments (Note 6)
Stockholders' Equity (Note 7):
Preferred stock, $0.01 par value Authorized - 500 shares, issued and outstanding - none
Common stock, $0.01 par value Authorized - 125,000 shares Issued - 22,432 and 21,719 shares as of December 31, 2017 and 2016, respectively Outstanding - 18,041 and 18,361 shares as of December 31, 2017 and 2016, respectively	224	217
Additional paid-in capital	181,910	157,569
Retained earnings	123,010	121,799
Treasury stock - 4,391 and 3,358 shares as of December 31, 2017 and 2016, respectively, at cost	(161,943)	(121,976)
Accumulated other comprehensive loss	(2,012)	(7,573)
Total stockholders’ equity	141,189	150,036
Total liabilities and stockholders’ equity	$ 345,200	$ 335,785

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	22,432,000	21,719,000
Common stock, shares outstanding	18,041,000	18,361,000
Treasury stock, shares	4,391,000	3,358,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Research services	$ 216,471	$ 215,216	$ 210,268
Advisory services and events	121,202	110,879	103,458
Total revenues	337,673	326,095	313,726
Operating expenses:
Cost of services and fulfillment	136,872	128,175	126,261
Selling and marketing	123,917	116,898	116,081
General and administrative	41,906	40,579	39,041
Depreciation	6,648	7,812	8,192
Amortization of intangible assets	781	831	891
Reorganization costs		1,026	4,433
Total operating expenses	310,124	295,321	294,899
Income from operations	27,549	30,774	18,827
Other income, net	301	740	511
Losses on investments, net	(479)	(805)	(18)
Income before income taxes	27,371	30,709	19,320
Income tax provision	12,231	13,058	7,324
Net income	$ 15,140	$ 17,651	$ 11,996
Basic income per common share	$ 0.84	$ 0.98	$ 0.67
Diluted income per common share	$ 0.83	$ 0.97	$ 0.66
Basic weighted average common shares outstanding	17,919	17,984	17,927
Diluted weighted average common shares outstanding	18,240	18,269	18,143

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 15,140	$ 17,651	$ 11,996
Other comprehensive income (loss), net of taxes:
Foreign currency translation	5,593	(2,764)	(3,187)
Net change in market value of investments	(32)	17	(26)
Other comprehensive income (loss)	5,561	(2,747)	(3,213)
Comprehensive income	$ 20,701	$ 14,904	$ 8,783

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2014	$ 141,602	$ 209	$ 124,942	$ 117,318	$ (99,254)	$ (1,613)
Beginning Balance, Shares at Dec. 31, 2014		20,856			2,703
Issuance of common stock under stock plans, including tax effects	1,680	$ 2	1,678
Issuance of common stock under stock plans, including tax effects, Shares		207
Stock-based compensation expense	8,347		8,347
Repurchases of common stock	(20,931)				$ (20,931)
Repurchase of common stock, Shares					608
Dividends paid on common shares	(12,179)			(12,179)
Net income	11,996			11,996
Net change in marketable investments, net of tax	(26)					(26)
Foreign currency translation	(3,187)					(3,187)
Ending Balance at Dec. 31, 2015	127,302	$ 211	134,967	117,135	$ (120,185)	(4,826)
Ending Balance, Shares at Dec. 31, 2015		21,063			3,311
Issuance of common stock under stock plans, including tax effects	14,632	$ 6	14,626
Issuance of common stock under stock plans, including tax effects, Shares		656
Stock-based compensation expense	7,976		7,976
Repurchases of common stock	(1,791)				$ (1,791)
Repurchase of common stock, Shares					47
Dividends paid on common shares	(12,987)			(12,987)
Net income	17,651			17,651
Net change in marketable investments, net of tax	17					17
Foreign currency translation	(2,764)					(2,764)
Ending Balance at Dec. 31, 2016	150,036	$ 217	157,569	121,799	$ (121,976)	(7,573)
Ending Balance, Shares at Dec. 31, 2016		21,719			3,358
Issuance of common stock under stock plans, including tax effects	15,979	$ 7	15,972
Issuance of common stock under stock plans, including tax effects, Shares		713
Cumulative effect adjustment due to adoption of new accounting pronouncements	(419)		(121)	(298)
Stock-based compensation expense	8,490		8,490
Repurchases of common stock	(39,967)				$ (39,967)
Repurchase of common stock, Shares					1,033
Dividends paid on common shares	(13,631)			(13,631)
Net income	15,140			15,140
Net change in marketable investments, net of tax	(32)					(32)
Foreign currency translation	5,593					5,593
Ending Balance at Dec. 31, 2017	$ 141,189	$ 224	$ 181,910	$ 123,010	$ (161,943)	$ (2,012)
Ending Balance, Shares at Dec. 31, 2017		22,432			4,391

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 15,140	$ 17,651	$ 11,996
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and asset write offs	6,648	7,812	8,350
Amortization of intangible assets	781	831	891
Net losses from investments	479	805	18
Deferred income taxes	6,425	2,602	(985)
Stock-based compensation	8,490	7,976	8,347
Amortization of premium on investments	207	345	693
Foreign currency (gains) losses	632	(81)	38
Changes in assets and liabilities
Accounts receivable	(10,327)	7,963	(718)
Deferred commissions	(1,679)	1,477	225
Prepaid expenses and other current assets	(4,146)	861	1,482
Accounts payable	(1,600)	1,317	(357)
Accrued expenses and other liabilities	7,857	58	6,116
Deferred revenue	8,586	(5,140)	(2,120)
Net cash provided by operating activities	37,493	44,477	33,976
Cash flows from investing activities:
Purchases of property and equipment	(7,861)	(4,140)	(3,931)
Purchases of marketable investments	(31,910)	(36,763)	(20,587)
Proceeds from sales and maturities of marketable investments	38,458	23,086	26,960
Other investing activity	343	(48)	347
Net cash provided by (used in) investing activities	(970)	(17,865)	2,789
Cash flows from financing activities:
Dividends paid on common stock	(13,631)	(12,987)	(12,179)
Repurchases of common stock	(39,967)	(1,791)	(20,931)
Proceeds from issuance of common stock under employee equity incentive plans	18,506	16,734	3,347
Taxes paid related to net share settlements of stock-based compensation awards	(2,527)	(2,069)	(1,459)
Net cash used in financing activities	(37,619)	(113)	(31,222)
Effect of exchange rate changes on cash and cash equivalents	3,928	(2,872)	(1,862)
Net increase in cash and cash equivalents	2,832	23,627	3,681
Cash and cash equivalents, beginning of year	76,958	53,331	49,650
Cash and cash equivalents, end of year	79,790	76,958	53,331
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$ 10,443	$ 8,507	$ 6,425

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(1) Summary of Significant Accounting Policies Basis of Presentation Principles of Consolidation Forrester Research, Inc. (“Forrester” or the “Company”) is a global independent research, data, and advisory services firm. Forrester works with business and technology leaders to help them develop customer-obsessed strategies that drive growth. Forrester’s unique insights are grounded in annual surveys of more than 675,000 consumers and business leaders worldwide, rigorous and objective research methodologies, and the shared wisdom of our clients. Through proprietary research and data, custom consulting, exclusive executive peer groups and events, Forrester challenges the thinking of its clients and positions them to lead change in their organizations. The accompanying consolidated financial statements include the accounts of Forrester and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Management Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Forrester considers the more significant of these estimates to be revenue recognition, non-marketable investments, goodwill and intangible assets, and income taxes. On an ongoing basis, management evaluates its estimates. Actual results could differ from these estimates. Fair Value Measurements The Company has certain financial assets recorded at fair value which have been classified as either Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. Level 1 — Fair value based on quoted prices in active markets for identical assets or liabilities. Level 2 — Fair value based on inputs other than Level 1 inputs that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Fair value based on unobservable inputs that are supported by little or no market activity and such inputs are significant to the fair value of the assets or liabilities. The carrying amounts reflected in the Consolidated Balance Sheets for cash, cash equivalents, accounts receivable, accounts payable, and accrued expenses approximate fair value due to their short-term maturities. Cash, Cash Equivalents, and Marketable Investments Forrester considers all short-term, highly liquid investments with original maturities at the time of purchase of 90 days or less to be cash equivalents. The Company’s portfolio of investments may at any time include securities of U.S. government agencies, municipal notes and bonds, corporate notes and bonds, commercial paper, and money market funds. Forrester accounts for all marketable investments as available-for-sale securities and as such, the marketable investments are carried at fair value with unrealized gains and losses (not related to credit losses) recorded in accumulated other comprehensive loss in the Consolidated Balance Sheets. Realized gains and losses on securities are included in earnings and are determined using the specific identification method. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments, as required under current accounting standards. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in accumulated other comprehensive loss. The determination of whether a loss is considered temporary is based in part on whether the Company intends to sell the security or whether the Company would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. During the years ended December 31, 2017, 2016 and 2015, the Company did not record any other-than-temporary impairment losses on its available-for-sale securities. Concentrations of Credit Risk Forrester has no off-balance sheet or significant concentration of credit risk such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject Forrester to concentrations of credit risk are principally cash, cash equivalents, marketable investments, and accounts receivable. Forrester places its investments in highly rated securities. No single customer accounted for greater than 2% of revenues or 3% of accounts receivable in any of the periods presented. Deferred Commissions Commissions incurred in acquiring new or renewing existing contracts, which are earned in the month that a contract is booked, are deferred and expensed to operations as the related revenue is recognized. Forrester evaluates the recoverability of deferred commissions at each balance sheet date. Goodwill Goodwill is not amortized; however, it is required to be tested for impairment annually. Furthermore, testing for impairment is required on an interim basis if an event or circumstance indicates that it is more likely than not an impairment loss has been incurred. An impairment loss would be recognized to the extent that the carrying amount of goodwill exceeds its implied fair value. Absent an event that indicates a specific impairment may exist, the Company has selected November 30th as the date for performing the annual goodwill impairment test. Goodwill impairment charges have not been required for the years ended December 31, 2017, 2016 and 2015. Impairment of Other Long-Lived Tangible and Intangible Assets Forrester continually evaluates whether events or circumstances have occurred that indicate that the estimated remaining useful life of long-lived assets and intangible assets may warrant revision or if events or circumstances indicate that the carrying value of these assets may be impaired. To compute whether assets have been impaired, the estimated undiscounted future cash flows for the estimated remaining useful life of the assets are compared to the carrying value. To the extent that the future cash flows are less than the carrying value, the assets are written down to the estimated fair value of the asset. Impairment charges have not been required for the years ended December 31, 2017, 2016 and 2015. Non-Current Liabilities The Company records certain liabilities that are expected to be settled over a period that exceeds one year as non-current liabilities. The Company also records as a non-current liability the portion of the deferred rent liability that is expected to be recognized over a period greater than one year. The non-current deferred rent liability at December 31, 2017 and 2016 was $7.5 million and $7.4 million, respectively, and results from the difference between cash payments and the straight-line recognition of rent expense under the Company’s facility leases. Foreign Currency The functional currency of the majority of Forrester’s wholly-owned subsidiaries is their respective local currency. These subsidiary financial statements are translated to U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates during the corresponding period for revenues and expenses, with translation gains and losses accumulated as a component of accumulated other comprehensive loss in the Consolidated Balance Sheets. Gains and losses related to the remeasurement of monetary assets and liabilities denominated in a currency other than an entity’s functional currency are included in other income, net in the Consolidated Statements of Income. For the years ended December 31, 2017 and 2016, Forrester recorded $0.6 million of foreign exchange losses and $0.1 million of foreign exchange gains, respectively, in other income, net. Foreign exchange losses were insignificant for the year ended December 31, 2015. Accumulated Other Comprehensive Income (Loss) The components of accumulated other comprehensive income (loss) are as follows (in thousands): Total Net Unrealized Gain Cumulative Accumulated (Loss) on Marketable Translation Other Comprehensive Investments Adjustment Income (Loss) Balance at December 31, 2014 $ (74 ) $ (1,539 ) $ (1,613 ) Foreign currency translation before reclassification — (3,505 ) (3,505 ) Reclassification adjustment for write-off of foreign currency translation loss — 318 318 Unrealized loss on investments, net of tax of $20 (26 ) — (26 ) Balance at December 31, 2015 (100 ) (4,726 ) (4,826 ) Foreign currency translation — (2,764 ) (2,764 ) Unrealized gain on investments, net of tax of ($14) 17 — 17 Balance at December 31, 2016 (83 ) (7,490 ) (7,573 ) Foreign currency translation — 5,593 5,593 Unrealized loss on investments, net of tax of $22 (32 ) — (32 ) Balance at December 31, 2017 $ (115 ) $ (1,897 ) $ (2,012 ) The reclassification adjustment for the write-off of a foreign currency translation loss relates to the liquidation of a non-U.S. subsidiary during 2015 and is reported in reorganization costs in the Consolidated Statements of Income. Revenue Recognition Forrester generates revenues from memberships to, and sales of, its Research, Connect and Analytics (rebranded from Data) products, performing advisory services and consulting projects and hosting Events. Forrester executes contracts that govern the terms and conditions of each arrangement. Revenues are recognized when persuasive evidence of an arrangement exists, the fee is fixed or determinable, services have been provided to the customer, and collectability is reasonably assured. Revenues are presented net of any sales or value added taxes that are collected from customers and remitted to the government. Revenue contracts may include either a single product or service or a combination of multiple products and services. Revenues from contracts that contain multiple products and services are allocated among the separate units of accounting based on their relative selling prices; however, the amount recognized is limited to the amount that is not contingent on future performance conditions. The Company obtains the relative selling prices of its products and services based on an analysis of standalone sales of these products and services during the year or upon an analysis of the estimated selling price of products for which there are insufficient standalone sales. The majority of research services revenues, including Research, Leadership Boards and the Analytics subscription products, are recognized ratably over the term of the contract. Research services revenues such as reprints are recognized as revenue when delivered. Advisory services revenues, such as workshops, speeches and advisory days, are recognized when the customer receives the agreed upon deliverable and consulting project revenues, which are short-term in nature and based upon fixed-fee agreements, are recognized as the services are provided. Event revenues are recognized upon completion of the Event. Reimbursed out-of-pocket expenses are recorded as advisory services and events revenue. Annual subscriptions to our Research include 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 and are accounted for as one unit of accounting. Annual subscriptions for Leadership Boards include 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. Leadership Boards are accounted for as two units of accounting: (1) the Event ticket and (2) the remaining services that are delivered throughout the contract period. Arrangement consideration is allocated to each of these elements based upon their relative selling prices, which is based on standalone sales of Event tickets and the estimated selling price of the remaining services. Annual subscriptions to our Analytics subscription products include access to designated survey data products and access to a data advisor, which are delivered throughout the contract period, and are accounted for as one unit of accounting and recognized ratably as research services revenue over the contract period. Certain of the Analytics subscription products also include advisory services and these contracts are accounted for as two units of accounting: (1) the subscription and data advisor and (2) the advisory services. Arrangement consideration is allocated to each element based upon its relative selling price, which is determined based on standalone sales of the advisory services and the estimated selling price of the remaining Analytics services. Stock-Based Compensation The Company recognizes the fair value of stock-based compensation expense over the requisite service period of the individual grantee, which generally equals the vesting period. The Company adopted the guidance in Accounting Standards Update ("ASU") No. 2016-09, Compensation - Stock Compensation Improvements to Employee Share-Based Payment Accounting Additionally, ASU No. 2016-09 requires that all income tax effects related to settlements of share-based payment awards be reported in earnings as an increase or decrease to income tax expense. Previously, income tax benefits at settlement of an award were reported as an increase (or decrease) to additional paid-in capital to the extent that those benefits were greater than (or less than) the income tax benefits reported in earnings during the award's vesting period. The requirement to report those income tax effects in earnings has been applied on a prospective basis to settlements occurring on or after January 1, 2017, and the impact of applying this guidance resulting in a $0.4 million decrease to income tax expense in the consolidated financial statements for the year ended December 31, 2017. ASU No. 2016-09 also requires that all income tax-related cash flows resulting from share-based payments be reported as operating activities in the statement of cash flows. Previously, income tax benefits at settlement of an award were reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award's vesting period. In addition, the standard requires that cash paid by directly withholding shares for tax withholding purposes be classified as a financing activity in the statement of cash flows. For the year ended December 31, 2017, the Company reflected $2.5 million of tax withholding in financing activities. The Company has elected to apply the changes in cash flow classification on a retrospective basis, resulting in an increase in operating cash flows, with a corresponding decrease in financing cash flows, of approximately $2.6 million and $1.5 million for the years ended December 31, 2016 and 2015, respectively, as compared to the amounts previously reported. Stock-based compensation expense was recorded in the following expense categories (in thousands): Years Ended December 31, 2017 2016 2015 Cost of services and fulfillment $ 4,538 $ 4,431 $ 4,573 Selling and marketing 717 1,054 1,152 General and administrative 3,235 2,491 2,622 Total $ 8,490 $ 7,976 $ 8,347 The options granted under the equity incentive plan and shares subject to the employee stock purchase plan were valued utilizing the Black-Scholes model using the following assumptions and had the following fair values (no options were granted in 2017): Years Ended December 31, 2017 2016 2015 Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Average risk-free interest rate 0.90 % 1.30 % 0.32 % 1.59 % 0.07 % Expected dividend yield 1.9 % 2.2 % 2.1 % 2.1 % 1.9 % Expected life 0.5 Years 5.0 Years 0.5 Years 5.0 Years 0.5 Years Expected volatility 24 % 24 % 24 % 24 % 22 % Weighted average fair value $ 8.36 $ 6.16 $ 6.69 $ 6.15 $ 7.19 Dividend yields are based on the initiation of a regular quarterly dividend program approved by the Board of Directors in February 2012. Expected volatility is based, in part, on the historical volatility of Forrester’s common stock as well as management’s expectations of future volatility over the expected term of the awards granted. The risk-free interest rate is based on the U.S. Treasury Constant Maturity rate with an equivalent remaining term. Where the expected term of a stock-based award does not correspond with a term for which the interest rates are quoted, Forrester uses the rate with the maturity closest to the award’s expected term. The expected term calculation is based upon Forrester’s historical experience of exercise patterns. The unamortized fair value of stock-based awards as of December 31, 2017 was $16.6 million, with a weighted average remaining recognition period of 2.6 years. Allowance for Doubtful Accounts Forrester maintains an allowance for doubtful accounts for estimated losses resulting from the inability of its customers to make contractually obligated payments. When evaluating the adequacy of the allowance for doubtful accounts, the Company makes judgments regarding the collectability of accounts receivable by specifically analyzing historical bad debts, customer concentrations, current economic trends, and changes in the customer payment terms. If the financial condition of the Company’s customers were to deteriorate, resulting in an impairment of their ability to make payments, additional allowances may be required and if the financial condition of the Company’s customers were to improve, the allowances may be reduced accordingly. Depreciation and Amortization Forrester provides for depreciation and amortization of property and equipment, computed using the straight-line method, over estimated useful lives of assets as follows: Estimated Useful Life Computers and equipment 3 to 10 Years Computer software 3 to 5 Years Furniture and fixtures 7 Years Leasehold improvements Shorter of asset life or lease term Forrester provides for amortization of intangible assets, computed using an accelerated method according to the expected cash flows to be received from the underlying assets, over the respective lives as follows: Estimated Useful Life Customer relationships 5 to 11 Years Research content 1 to 2 Years Technology 7 Years Income Taxes Forrester recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statements and tax basis of assets and liabilities as well as operating loss carryforwards. Forrester’s provision for income taxes is composed of a current and a deferred provision for federal, state and foreign jurisdictions. The current provision is calculated as the estimated taxes payable or refundable on tax returns for the current year. The deferred income tax provision is calculated as the net change during the year in deferred tax assets and liabilities. Valuation allowances are provided if based on the weight of available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. Forrester accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity, and changes in facts or circumstances related to a tax position. The Company evaluates these tax positions on a quarterly basis. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense. The Company elected to early adopt the guidance in ASU No. 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory Net Income Per Common Share Basic net income per common share is computed by dividing net income by the basic weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the diluted weighted average number of common shares and common equivalent shares outstanding during the period. The weighted average number of common equivalent shares outstanding has been determined in accordance with the treasury-stock method. Common stock equivalents consist of common stock issuable upon the exercise of outstanding stock options and the vesting of restricted stock units. Basic and diluted weighted average common shares are as follows (in thousands): Years Ended December 31, 2017 2016 2015 Basic weighted average common shares outstanding 17,919 17,984 17,927 Weighted average common equivalent shares 321 285 216 Diluted weighted average common shares outstanding 18,240 18,269 18,143 Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive 133 706 1,237 New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers: Principal versus Agent Considerations Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing , Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients Technical Corrections and Improvements: Revenue from Contracts with Customers The new standard will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company will adopt the standard as of January 1, 2018 utilizing the modified retrospective method. The Company does not anticipate that the standard will have a material impact on its results of operations. The number of performance obligations in the Company’s arrangements will not be different under the new standard. Determining standalone selling prices and allocating contract consideration on multiple element arrangements will not be different from the Company’s current methodologies of establishing fair value and estimated selling price for our goods and services or allocating total contract consideration under the relative selling price method. Additionally, the timing of revenue recognition will remain substantially unchanged for most products. Subscription based research services revenues will continue to be recognized over time, using the new standard’s output method of time elapsed, as Forrester’s clients receive and consume the benefits of its services as the Company transfers control throughout the contract period. Advisory, reprint and Events revenues will continue to be recognized at the point in time as control is transferred to the customer, which will generally be when the client has physical possession of the good(s) or upon completion of the service(s). The Company expects that most of its consulting contracts will continue to be recognized over time, while some contracts may be required to be recognized at a point in time upon completion of the project. The following changes are anticipated under the new standard: • The Company will no longer record accounts receivable and deferred revenue on its balance sheet when it issues an invoice to a customer for a contract that is cancellable by the customer. For contracts that are cancellable, the Company will only record accounts receivable up to the amount of revenue earned but not yet collected. This change will have the effect of reducing the amount of accounts receivable and deferred revenue on the balance sheet compared to amounts recorded based on current accounting standards. The majority of the Company’s contracts are non-cancellable; however, the Company has not yet determined the effect of this change on its balance sheet. • The timing of revenue recognition for prepaid performance obligations that are expected to expire unused, which may include Event tickets, reprints and advisory hours, will change from recognition at the time of expiration under the current standard to recognition in proportion to the pattern of related rights exercised by the customer. The Company currently expects this change to primarily affect the timing of revenue within the quarters of 2018 but does not expect it to have a material effect on the Company’s results of operations for the full year of 2018. • Costs to fulfill contracts, such as our survey costs for our Analtyics product line, are currently deferred and recognized over the aggregate period of the contracts under the current standards. These costs will be recognized as incurred under the new standard, which the Company expects will have an immaterial effect on the results of operations for the full year of 2018, however it will change the timing of the recognition of the costs on a quarterly basis as compared to the current standards. Key areas still in process include the calculation of the cumulative effect adjustment for the adoption of the standard, which will be recorded as of January 1, 2018, and development of reports for the various disclosures required in 2018. These areas will be completed by the end of the first quarter of 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other: Simplifying the Test for Goodwill Impairment

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	(2) Goodwill and Other Intangible Assets A summary of the goodwill by segment and the changes in the carrying amount of goodwill is shown in the following table (in thousands). Project Product Research Consulting Total Balance at January 1, 2016 $ 2,371 $ 71,700 $ — $ 74,071 Translation adjustments (28 ) (850 ) — (878 ) Balance at December 31, 2016 2,343 70,850 — 73,193 Translation adjustments 95 2,881 — 2,976 Balance at December 31, 2017 $ 2,438 $ 73,731 $ — $ 76,169 As of December 31, 2017, the Company had no accumulated goodwill impairment losses. A summary of Forrester’s intangible assets is as follows (in thousands): December 31, 2017 Gross Net Carrying Accumulated Carrying Amount Amortization Amount Amortizable intangible assets: Customer relationships $ 31,735 $ 31,003 $ 732 Research content 1,083 1,083 — Total $ 32,818 $ 32,086 $ 732 December 31, 2016 Gross Net Carrying Accumulated Carrying Amount Amortization Amount Amortizable intangible assets: Customer relationships $ 30,998 $ 29,534 $ 1,464 Research content 1,083 1,083 — Total $ 32,081 $ 30,617 $ 1,464 Amortization expense related to intangible assets was approximately $0.8 million, $0.8 million and $0.9 million during the years ended December 31, 2017, 2016 and 2015, respectively. The remaining net book value of $0.7 million as of December 31, 2017 will be fully amortized during 2018.

Marketable Investments

Marketable Investments	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Marketable Investments	(3) Marketable Investments The following table summarizes the Company’s marketable investments, all of which are classified as available-for-sale (in thousands): As of December 31, 2017 Gross Gross Amortized Unrealized Unrealized Market Cost Gains Losses Value Federal agency obligations $ 1,800 $ — $ (7 ) $ 1,793 Corporate obligations 52,721 — (181 ) 52,540 Total $ 54,521 $ — $ (188 ) $ 54,333 As of December 31, 2016 Gross Gross Amortized Unrealized Unrealized Market Cost Gains Losses Value Federal agency obligations $ 1,800 $ — $ (7 ) $ 1,793 Corporate obligations 59,481 2 (129 ) 59,354 Total $ 61,281 $ 2 $ (136 ) $ 61,147 The following table summarizes the maturity periods of the marketable investments in the Company’s portfolio as of December 31, 2017. FY 2018 FY 2019 Total Federal agency obligations $ 1,793 $ — $ 1,793 Corporate obligations 31,494 21,046 52,540 Total $ 33,287 $ 21,046 $ 54,333 The following table shows the gross unrealized losses and market value of Forrester’s available-for-sale securities with unrealized losses that are not deemed to be other-than-temporary, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands): As of December 31, 2017 Less Than 12 Months 12 Months or Greater Market Unrealized Market Unrealized Value Losses Value Losses Federal agency obligations $ — $ — $ 1,793 $ 7 Corporate obligations 31,723 149 20,817 32 Total $ 31,723 $ 149 $ 22,610 $ 39 As of December 31, 2016 Less Than 12 Months 12 Months or Greater Market Unrealized Market Unrealized Value Losses Value Losses Federal agency obligations $ 1,793 $ 7 $ — $ — Corporate obligations 53,647 129 — — Total $ 55,440 $ 136 $ — $ — Realized gains or losses on sales of the Company’s available-for-sale securities were not significant for the years ended December 31, 2017 and 2016. The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and marketable investments) measured at fair value on a recurring basis (in thousands): As of December 31, 2017 Level 1 Level 2 Level 3 Total Money market funds (1) $ 492 $ — $ — $ 492 Federal agency obligations — 1,793 — 1,793 Corporate obligations — 52,540 — 52,540 Total $ 492 $ 54,333 $ — $ 54,825 As of December 31, 2016 Level 1 Level 2 Level 3 Total Money market funds (1) $ 2,522 $ — $ — $ 2,522 Federal agency obligations — 1,793 — $ 1,793 Corporate obligations — 59,354 — 59,354 Total $ 2,522 $ 61,147 $ — $ 63,669 (1) Included in cash and cash equivalents. Level 2 assets consist of the Company’s entire portfolio of marketable investments. Level 2 assets have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing third party pricing services or other market observable data. The pricing services utilize industry standard valuation methods, including both income and market based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events.

Non-Marketable Investments

Non-Marketable Investments	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Non-Marketable Investments	(4) Non-Marketable Investments At December 31, 2017 and 2016, the carrying value of the Company’s non-marketable investments, which were composed primarily of interests in technology-related private equity funds, was $1.9 million and $2.8 million, respectively, and are included in other assets in the Consolidated Balance Sheets. The Company’s investments are being accounted for using the equity method as the investments are limited partnerships and the Company has an ownership interest in excess of 5% and, accordingly, the Company records its share of the investee’s operating results each period. At December 31, 2016, the Company’s investments also included an investment with a book value of $0.4 million, which was accounted for using the cost method. This investment was fully liquidated during 2017. During the years ended December 31, 2017 and 2016, the Company recorded losses from its non-marketable investments of $0.5 million and $0.8 million, respectively, which are included in losses on investments, net in the Consolidated Statements of Income. During the year ended December 31, 2015, losses from non-marketable investments were insignificant. During the year ended December 31, 2017, a gross distribution of $0.4 million was received from the funds. During the year ended December 31, 2016, no distributions were received from the funds. During the year ended December 31, 2015, a gross distribution of $0.1 million was received from the funds.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	(5) Income Taxes Income before income taxes consists of the following (in thousands): Years Ended December 31, 2017 2016 2015 Domestic $ 20,061 $ 22,303 $ 11,347 Foreign 7,310 8,406 7,973 Total $ 27,371 $ 30,709 $ 19,320 The components of the income tax provision (benefit) are as follows (in thousands): Years Ended December 31, 2017 2016 2015 Current: Federal $ 2,587 $ 6,094 $ 5,103 State 1,060 2,330 1,252 Foreign 2,159 2,032 1,954 Total current 5,806 10,456 8,309 Deferred: Federal 5,550 2,719 (723 ) State 700 59 (232 ) Foreign 175 (176 ) (30 ) Total deferred 6,425 2,602 (985 ) Income tax provision $ 12,231 $ 13,058 $ 7,324 A reconciliation of the federal statutory rate to Forrester’s effective tax rate is as follows: Years Ended December 31, 2017 2016 2015 Income tax provision at federal statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in tax resulting from: State tax provision, net of federal benefit 4.0 5.0 4.0 Foreign tax rate differential (3.4 ) (4.4 ) (3.0 ) Stock option compensation deduction 0.1 0.6 2.5 Withholding taxes 1.7 0.5 0.3 Non-deductible expenses 1.8 1.5 1.7 Change in valuation allowance 3.9 3.2 (0.7 ) Change in tax legislation 5.8 — (3.1 ) Audit settlements (4.0 ) — — Other, net (0.2 ) 1.1 1.2 Effective tax rate 44.7 % 42.5 % 37.9 % On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the “Act”) was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a decrease in the corporate tax rate from 35% to 21% effective for tax years beginning after December 31, 2017, the transition of U.S international taxation from a worldwide tax system to a modified territorial system, and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. The Company has calculated its best estimate of the impact of the Act in its 2017 income tax provision in accordance with the Company’s understanding of the Act and guidance available as of the date of this filing and as a result have recorded $1.6 million as additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted. The provisional amount related to the remeasurement of federal deferred tax assets and liabilities was $1.2 million. The provisional amount related to the one-time transition tax on the mandatory deemed repatriation of foreign earnings was $0.4 million based on cumulative foreign earnings of $22.6 million. On December 22, 2017, Staff Accounting Bulletin No. 118 ("SAB 118") was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. S A 11 p r ov i d e ea u r e e n p e r i o t h a hou l no e x t e n b e yon on y ea fr o t h e n ac t e n d a t of the Act f o c o p a n i e t c o p l e t t h acc oun ti n for the income tax effects of the Act I acc o r d a n c w it S A 118 c o p a n u r e f l ec t h i n c o t a e ff ec t o t ho a p ec t o t h A c f o w h i c t h acc oun ti n und e i c o p l e t e T t h e x t e n t h a c o p a ny ’ acc oun ti n f o ce r t a i i n c o t a e ff ec t o t h A c i i n c o p l e t bu i i a b l t d e t e r i n r ea on a b l e ti a t e i u r ec o r a p r ov i i on a e ti a t i t h f i n a n c i a t a t e e n t A the Company c o p l e its a n a l y i o t h A c t c o ll ec a n p r e p a r n ece a r d a t a a n i n t e r p r e a n a dd iti on a gu i d a n c i u e b t h U . S T r ea u r D e p a r t e n t t h I R S a n o t h e t a nd a r d - e tti n bod i e the Company a a k a d j u t e n t t t h p r ov i i on a a oun t In July 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. The opinion invalidates part of a treasury regulation requiring stock-based compensation to be included in any qualified intercompany cost-sharing arrangement. The Company has reviewed this case and concluded that recording a tax benefit of $0.6 million during 2015, representing the benefit of adjusting its cost-sharing agreement for the years of 2012 through 2014, was appropriate based on the opinion in the case. This benefit is included in the change in tax legislation line in the table above. There were no significant developments in this case during 2017 and the Company will continue to monitor ongoing developments and potential impacts to its consolidated financial statements. The components of deferred income taxes are as follows (in thousands): As of December 31, 2017 2016 Non-deductible reserves and accruals $ 4,936 $ 8,189 Net operating loss and other carryforwards 8,528 7,560 Stock compensation 2,644 5,327 Depreciation and amortization 402 1,196 Other assets 46 50 Gross deferred tax asset 16,556 22,322 Less - valuation allowance (2,686 ) (2,193 ) Sub-total 13,870 20,129 Other liabilities (911 ) (453 ) Goodwill amortization (5,677 ) (5,013 ) Deferred commissions (3,873 ) (4,928 ) Net deferred tax asset $ 3,409 $ 9,735 As of December 31, 2017 and 2016, long-term net deferred tax assets were $3.5 million and $9.8 million, respectively, and are included in other assets in the Consolidated Balance Sheets. Long-term net deferred tax liabilities were $0.1 million at December 31, 2017 and 2016, and are included in non-current liabilities in the Consolidated Balance Sheets. The Company considers all available evidence, both positive and negative, to determine whether, based on the weight of that evidence, a valuation allowance is needed for some portion or all of a net deferred income tax asset. Judgment is required in considering the relative impact of negative and positive evidence. In arriving at these judgments, the weight given to the potential effect of negative and positive evidence is commensurate with the extent to which it can be objectively verified. Although realization is not assured, based upon the Company’s historical taxable income and projections of the Company’s future taxable income over the periods during which the deferred tax assets are deductible and the carryforwards expire, management believes it is more likely than not that the Company will realize the benefits of these deductible differences, net of the existing valuation allowances, as discussed below. As of December 31, 2017 and 2016, the Company maintained a valuation allowance of approximately $2.7 million and $2.2 million, respectively, primarily relating to U.S. capital losses from the Company’s investment in technology-related private equity funds, and from foreign net operating loss carryforwards from an acquisition. As of December 31, 2017, the Company has fully utilized its U.S. federal net operating loss carryforwards. The Company has foreign net operating loss carryforwards of approximately $22.4 million, which can be carried forward indefinitely. Approximately $3.6 million of the foreign net operating loss carryforwards relate to a prior acquisition, the utilization of which is subject to limitation under the tax law of the United Kingdom. As of December 31, 2017, the Company had U.S. federal and state capital loss carryforwards of $6.6 million, of which $0.4 million expires in 2018, $1.6 million expires in 2020, $1.4 million expires in 2021, and $3.2 million expires in 2022. The following table provides a summary of the changes in the deferred tax valuation allowance for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Deferred tax valuation allowance at January 1 $ 2,193 $ 1,534 $ 1,565 Additions 1,439 1,256 150 Deductions (70 ) (455 ) (134 ) Change in tax legislation (954 ) — — Translation adjustments 78 (142 ) (47 ) Deferred tax valuation allowance at December 31 $ 2,686 $ 2,193 $ 1,534 T h A c i n c l ud e a nd a t o r on e - ti t a o acc u u l a t e ea r n i ng o f o r e i g ub i d i a r i e a n a r e u lt a l p r e v i ou l un r e itt e ea r n i ng f o w h i c n U . S d e f e rr e t a li a b ilit h a b ee acc r u e h a v no b ee ub j ec t U . S t a x N o t w it h t a nd i n t h U . S t a x a ti o o t h e a oun t the Company i n t e n t c on ti nu t i nv e a l o t h e ea r n i ng a w e l a the ca p it a i t h e ub i d i a r i e i nd e f i n it e l ou t i d o t h U . S a n d no e xp ec t i n c u a n i gn i f i ca n t a dd iti on a r e l a t e t u c a oun t The Company utilizes a two-step process for the measurement of uncertain tax positions that have been taken or are expected to be taken on a tax return. The first step is a determination of whether the tax position should be recognized in the financial statements. The second step determines the measurement of the tax position. A reconciliation of the beginning and ending amount of unrecognized tax benefits is summarized as follows for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Unrecognized tax benefits at January 1 $ 1,774 $ 1,910 $ 2,136 Additions for tax positions of prior years — — 36 Reductions for tax positions of prior years — (31 ) — Additions for tax positions of current year — 75 46 Settlements (986 ) (163 ) (303 ) Lapse of statute of limitations — — — Translation adjustments 18 (17 ) (5 ) Unrecognized tax benefits at December 31 $ 806 $ 1,774 $ 1,910 As of December 31, 2017, the total amount of unrecognized tax benefits totaled approximately $0.8 million, all of which if recognized, would decrease our effective tax rate in a future period. It is reasonably possible that $0.4 million of this amount may be settled within the next 12 months as the Company expects to reach a settlement with U.S. Competent Authority on the treatment of a prior year foreign tax payment. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense and such amounts were not significant in the years ended December 31, 2017, 2016 and 2015. At December 31, 2016 and 2015, the Company had $0.1 million and $0.2 million, respectively, of accrued interest and penalties related to uncertain tax positions. Accrued interest and penalties were insignificant at December 31, 2017. The Company files income tax returns in the U.S. and in foreign jurisdictions. Generally, the Company is no longer subject to U.S., state, local and foreign income tax examinations by tax authorities in its major jurisdictions for years before 2012, except to the extent of net operating loss and tax credit carryforwards from those years. Major taxing jurisdictions include the U.S., the Netherlands, the United Kingdom, Germany and Switzerland. As of December 31, 2017, the Company was not under any audits.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments	(6) Commitments As of December 31, 2017, Forrester had future contractual obligations as follows for operating leases (in thousands): 2018 $ 12,506 2019 11,442 2020 10,835 2021 9,409 2022 8,001 Thereafter 29,490 Total minimum lease payments $ 81,683 The cost of these operating leases, including any contractual rent increases, rent concessions, and landlord incentives, are recognized ratably over the life of the related lease agreement. Aggregate rent expense was $17.4 million, $16.1 million and $16.0 million for the years ended December 31, 2017, 2016, and 2015, respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	(7) Stockholders’ Equity Preferred Stock Forrester has authorized 500,000 shares of $0.01 par value preferred stock. The Board of Directors has full authority to issue this stock and to fix the voting powers, preferences, rights, qualifications, limitations, or restrictions thereof, including dividend rights, conversion rights, redemption privileges and liquidation preferences and the number of shares constituting any series or designation of such series. Treasury Stock Through 2017, Forrester’s Board of Directors has authorized an aggregate $485.0 million to purchase common stock under its stock repurchase program including $25.0 million authorized in each of October 2016, February 2015 and July 2015. The shares repurchased may be used, among other things, in connection with Forrester’s equity incentive and purchase plans. As of December 31, 2017, the Company had repurchased approximately 16.1 million shares of common stock at an aggregate cost of $464.9 million. Dividends During the years ended December 31, 2017, 2016 and 2015, the Company declared and paid four quarterly dividends of $0.19, $0.18 and $0.17 per share each quarter, respectively, amounting to $0.76 per share or $13.6 million, $0.72 per share or $13.0 million and $0.68 per share or $12.2 million, respectively. Equity Plans Forrester maintains the following two equity incentive plans: the Forrester Research, Inc. Amended and Restated Equity Incentive Plan (the “Equity Incentive Plan” and previously the “2006 Plan”) and the 2006 Stock Option Plan for Directors, as amended (the “2006 Directors’ Plan”). Upon approval of an amendment to the 2006 Plan by stockholders in 2012, no future awards under the 2006 Directors’ Plan could be granted or issued. In May 2016, the stockholders of the Company approved an amendment and restatement of the Company’s 2006 Plan. The amendment and restatement resulted in (1) extending the term of the plan for 10 years until May 2026, (2) increasing the number of shares issuable under the plan by 2,000,000 shares, (3) establishing a maximum amount of awards issuable under the plan to the Company’s non-employee directors, and (4) changing the name of the plan to the Forrester Research, Inc. Amended and Restated Equity Incentive Plan The Equity Incentive Plan provides for the issuance of stock-based awards, including incentive stock options (“ISOs”), non-qualified stock options (“NSOs”), and restricted stock units (“RSUs”) to purchase up to 6,350,000 shares authorized in the plan, 80,000 shares returned from the 2006 Directors’ Plan and 713,275 shares returned from a prior plan. Under the terms of the Equity Incentive Plan, ISOs may not be granted at less than fair market value on the date of grant (and in no event less than par value). Options and RSUs generally vest annually over four years and options expire after 10 years. Beginning in 2017, RSUs granted to non-employee directors vest quarterly over one year. Options and RSUs granted under the Equity Incentive Plan immediately vest upon certain events, as described in the plan. As of December 31, 2017, approximately 2.6 million shares were available for future grant of awards under the Equity Incentive Plan. The 2006 Directors’ Plan provided for the issuance of options to purchase up to 450,000 shares of common stock. As of December 31, 2017, approximately 0.1 million options remain outstanding and are fully vested under the 2006 Directors’ Plan. Restricted Stock Units Restricted stock units (“RSUs”) represent the right to receive one share of Forrester common stock when the restrictions lapse and the vesting conditions are met, and are valued on the date of grant based upon the value of the Company’s stock on the date of grant less the present value of dividends expected to be paid during the requisite service period. Shares of Forrester’s common stock will be delivered to the grantee upon vesting, subject to a reduction of shares for payment of withholding taxes. The weighted average grant date fair value for RSUs granted in 2017, 2016 and 2015 was $39.73, $37.87 and $31.50, respectively. The value of RSUs vested and converted to common stock, based on the value of Forrester’s common stock on the date of vesting, was $8.7 million, $6.6 million and $4.6 million during 2017, 2016 and 2015, respectively. RSU activity for the year ended December 31, 2017 is presented below (in thousands, except per share data): Weighted- Average Number of Grant Date Shares Fair Value Unvested at December 31, 2016 539 $ 35.50 Granted 253 39.73 Vested (212 ) 35.38 Forfeited (71 ) 35.92 Unvested at December 31, 2017 509 $ 37.59 Stock Options Stock option activity for the year ended December 31, 2017 is presented below (in thousands, except per share data and contractual term): Weighted - Weighted - Average Average Exercise Remaining Aggregate Number Price Per Contractual Intrinsic of Shares Share Term (in years) Value Outstanding at December 31, 2016 1,540 $ 34.35 Granted — — Exercised (512 ) 32.90 Forfeited (91 ) 34.87 Outstanding at December 31, 2017 937 $ 35.10 5.86 $ 8,529 Exercisable at December 31, 2017 650 $ 34.98 5.16 $ 5,992 Vested and expected to vest at December 31, 2017 937 $ 35.10 5.86 $ 8,529 The total intrinsic value of options exercised during 2017, 2016 and 2015 was $4.5 million, $3.7 million and $0.4 million, respectively. Employee Stock Purchase Plan The Amended and Restated Employee Stock Purchase Plan (the “Stock Purchase Plan”) provides for the issuance of up to 0.7 million shares of common stock and as of December 31, 2017 approximately 0.1 million shares remain available for issuance. With certain limited exceptions, all employees of Forrester whose customary employment is more than 20 hours per week, including officers and directors who are employees, are eligible to participate in the Stock Purchase Plan. Purchase periods under the Stock Purchase Plan are generally six months in length and commence on each successive March 1 and September 1. Stock purchased under the Stock Purchase Plan is required to be held for one year before it is able to be sold. During each purchase period the maximum number of shares of common stock that may be purchased by an employee is limited to the number of shares equal to $12,500 divided by the fair market value of a share of common stock on the first day of the purchase period. An employee may elect to have up to 10% deducted from his or her compensation for the purpose of purchasing shares under the Stock Purchase Plan. The price at which the employee’s shares are purchased is the lower of: (a) 85% of the closing price of the common stock on the day that the purchase period commences, or (b) 85% of the closing price of the common stock on the day that the purchase period terminates. Shares purchased by employees under the Stock Purchase Plan are as follows (in thousands, except per share data): Shares Purchase Purchase Period Ended Purchased Price February 28, 2017 24 $ 31.03 August 31, 2017 26 $ 31.71 February 29, 2016 28 $ 26.00 August 31, 2016 25 $ 27.04

Employee Pension Plans

Employee Pension Plans	12 Months Ended
	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Employee Pension Plans	(8) Employee Pension Plans Forrester sponsors several defined contribution plans for eligible employees. Generally, the defined contribution plans have funding provisions which, in certain situations, require contributions based upon formulas relating to employee wages or the level of elective participant contributions, as well as allow for additional discretionary contributions. Further, certain plans contain vesting provisions. Forrester’s contributions to these plans totaled approximately $5.2 million, $4.3 million and $4.1 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Reorganization

Reorganization	12 Months Ended
	Dec. 31, 2017
Restructuring And Related Activities [Abstract]
Reorganization	(9) Reorganization In the first quarter of 2016, the Company implemented and completed a reduction in its workforce of approximately 2% of its employees across various geographies and functions. The Company incurred $1.0 million of severance and related costs for this action. In the first quarter of 2015, the Company implemented a reduction in its workforce of approximately 4% of its employees across various geographies and functions, in order to reallocate investment in 2015 to planned sales expansion and to delivery areas seeing the greatest client demand. The Company recorded $3.2 million of severance and related costs for this action. In addition, the Company incurred an additional $0.3 million charge related to the action primarily for a non-cash charge for the liquidation of a small non-U.S. subsidiary. In the third quarter of 2015, the Company implemented a reorganization of its Products Group and incurred $0.7 million of severance and related benefits for the termination of the chief product officer and related administrative staff and the termination of a senior product leader with the intent to relocate this position to the U.S. In addition, as a result of the change in leadership in the Products Group, the Company incurred $0.2 million of expense to write off a software development project that was no longer deemed probable to be completed. The activity related to the reorganization accrual during the year ended December 31, 2016 is as follows (in thousands): Workforce Subsidiary Products Reduction Liquidation Reorganization Total Accrual at December 31, 2015 $ 41 $ 7 $ 433 $ 481 Additions 1,022 — 4 1,026 Cash payments (1,063 ) (7 ) (437 ) (1,507 ) Accrual at December 31, 2016 $ — $ — $ — $ —

Operating Segment and Enterpris

Operating Segment and Enterprise Wide Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Operating Segment and Enterprise Wide Reporting	(10) Operating Segment and Enterprise Wide Reporting The Product segment includes the costs of the product management organization that is responsible for product pricing and packaging and the launch of new products. In addition, this segment includes the costs of the Company’s Analytics, Connect and Events organizations. Revenue in this segment includes all revenue for the Company (including Research and Connect) except for revenue from advisory services and project consulting services that are delivered by personnel in the Research and Project Consulting segments. The Research segment includes the costs of the Company’s research personnel who are responsible for writing the research and performing the webinars and inquiries for the Company’s Research and Connect products. In addition, the research personnel deliver advisory services (such as workshops, speeches and advisory days) and a portion of the Company’s project consulting services. Revenue in this segment includes only revenue from advisory services and project consulting services that are delivered by the research personnel in this segment. The Project Consulting segment includes the costs of the consultants that deliver the majority of the Company’s project consulting services. Revenue in this segment includes the project consulting revenue delivered by the consultants in this segment. The Company evaluates reportable segment performance and allocates resources based on segment revenues and expenses. Segment expenses include the direct expenses of each segment organization and exclude selling and marketing expenses, general and administrative expenses, stock-based compensation expense, depreciation expense, adjustments to incentive bonus compensation from target amounts, amortization of intangible assets, reorganization costs, other income and losses on investments. The accounting policies used by the segments are the same as those used in the consolidated financial statements. The Company does not identify or allocate assets, including capital expenditures, by operating segment. Accordingly, assets are not being reported by segment because the information is not available by segment and is not reviewed in the evaluation of performance or making decisions in the allocation of resources. In 2017, the Company modified its internal reporting for the Research and Project Consulting segments to reflect the transfer of revenue and direct costs related to a small consulting team in Asia Pacific from Research to Project Consulting, and to remove from both Research and Project Consulting certain client support activities that are now included within selling, marketing, administrative and other expenses in the table below. Accordingly, the 2016 and 2015 amounts have been reclassified to conform to the current presentation. The following tables present information about reportable segments (in thousands): Project Product Research Consulting Consolidated Year Ended December 31, 2017 Research services revenues $ 216,471 $ — $ — $ 216,471 Advisory services and events revenues 21,887 45,054 54,261 121,202 Total segment revenues 238,358 45,054 54,261 337,673 Segment expenses 45,205 48,812 25,477 119,494 Contribution margin (loss) 193,153 (3,758 ) 28,784 218,179 Selling, marketing, administrative and other expenses (189,849 ) Amortization of intangible assets (781 ) Reorganization costs — Other income and losses on investments (178 ) Income before income taxes $ 27,371 Project Product Research Consulting Consolidated Year Ended December 31, 2016 Research services revenues $ 215,216 $ — $ — $ 215,216 Advisory services and events revenues 20,374 44,631 45,874 110,879 Total segment revenues 235,590 44,631 45,874 326,095 Segment expenses 41,528 47,496 23,141 112,165 Contribution margin (loss) 194,062 (2,865 ) 22,733 213,930 Selling, marketing, administrative and other expenses (181,299 ) Amortization of intangible assets (831 ) Reorganization costs (1,026 ) Other income and losses on investments (65 ) Income before income taxes $ 30,709 Project Product Research Consulting Consolidated Year Ended December 31, 2015 Research services revenues $ 210,268 $ — $ — $ 210,268 Advisory services and events revenues 17,512 42,422 43,524 103,458 Total segment revenues 227,780 42,422 43,524 313,726 Segment expenses 38,615 48,277 23,292 110,184 Contribution margin (loss) 189,165 (5,855 ) 20,232 203,542 Selling, marketing, administrative and other expenses (179,391 ) Amortization of intangible assets (891 ) Reorganization costs (4,433 ) Other income and losses on investments 493 Income before income taxes $ 19,320 Net long-lived tangible assets by location as of December 31, 2017 and 2016 are as follows (in thousands): 2017 2016 United States $ 23,943 $ 22,150 United Kingdom 727 782 Europe (excluding United Kingdom) 163 259 Other 416 703 Total $ 25,249 $ 23,894 Revenues by geographic destination and as a percentage of total revenues for the years ended December 31, 2017, 2016, and 2015 are as follows (dollars in thousands): 2017 2016 2015 United States $ 260,077 $ 252,222 $ 241,025 Europe (excluding United Kingdom) 28,525 27,061 24,607 United Kingdom 13,651 14,808 16,815 Canada 14,523 13,806 14,424 Other 20,897 18,198 16,855 Total $ 337,673 $ 326,095 $ 313,726 2017 2016 2015 United States 77 % 77 % 77 % Europe (excluding United Kingdom) 9 8 8 United Kingdom 4 5 5 Canada 4 4 5 Other 6 6 5 Total 100 % 100 % 100 %

Certain Balance Sheet Accounts

Certain Balance Sheet Accounts	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Certain Balance Sheet Accounts	(11) Certain Balance Sheet Accounts Property and Equipment: Property and equipment as of December 31, 2017 and 2016 is recorded at cost less accumulated depreciation and consists of the following (in thousands): 2017 2016 Computers and equipment $ 18,570 $ 17,137 Computer software 29,891 26,686 Furniture and fixtures 9,094 8,471 Leasehold improvements 26,650 25,204 Total property and equipment 84,205 77,498 Less accumulated depreciation 58,956 53,604 Total $ 25,249 $ 23,894 Accrued Expenses and Other Current Liabilities: Accrued expenses and other current liabilities as of December 31, 2017 and 2016 consist of the following (in thousands): 2017 2016 Payroll and related benefits $ 34,809 $ 28,681 Taxes 3,912 4,704 Other 10,908 8,018 Total $ 49,629 $ 41,403 Allowance for Doubtful Accounts: A roll-forward of the allowance for doubtful accounts as of and for the years ended December 31, 2017, 2016, and 2015 is as follows (in thousands): 2017 2016 2015 Balance, beginning of year $ 140 $ 153 $ 188 Provision for doubtful accounts 331 150 106 Write-offs (316 ) (163 ) (141 ) Balance, end of year $ 155 $ 140 $ 153

Summary Selected Quarterly Fina

Summary Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary Selected Quarterly Financial Data (Unaudited)	(12) Summary Selected Quarterly Financial Data (unaudited) The following is a summary of selected unaudited consolidated quarterly financial data for the years ended December 31, 2017 and 2016 (in thousands, except per share data): Three Months Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Total revenues $ 77,194 $ 89,733 $ 80,369 $ 90,377 Income from operations $ 3,136 $ 10,213 $ 6,749 $ 7,451 Net income $ 3,030 $ 6,064 $ 3,953 $ 2,093 Basic income per common share $ 0.17 $ 0.34 $ 0.22 $ 0.12 Diluted income per common share $ 0.16 $ 0.34 $ 0.22 $ 0.11 Three Months Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Total revenues $ 77,401 $ 87,821 $ 77,427 $ 83,446 Income from operations $ 2,712 $ 11,472 $ 7,552 $ 9,038 Net income $ 1,289 $ 7,460 $ 3,112 $ 5,790 Basic income per common share $ 0.07 $ 0.42 $ 0.17 $ 0.32 Diluted income per common share $ 0.07 $ 0.41 $ 0.17 $ 0.31

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Principles of Consolidation Forrester Research, Inc. (“Forrester” or the “Company”) is a global independent research, data, and advisory services firm. Forrester works with business and technology leaders to help them develop customer-obsessed strategies that drive growth. Forrester’s unique insights are grounded in annual surveys of more than 675,000 consumers and business leaders worldwide, rigorous and objective research methodologies, and the shared wisdom of our clients. Through proprietary research and data, custom consulting, exclusive executive peer groups and events, Forrester challenges the thinking of its clients and positions them to lead change in their organizations. The accompanying consolidated financial statements include the accounts of Forrester and its wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Management Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Forrester considers the more significant of these estimates to be revenue recognition, non-marketable investments, goodwill and intangible assets, and income taxes. On an ongoing basis, management evaluates its estimates. Actual results could differ from these estimates.
Fair Value Measurements	Fair Value Measurements The Company has certain financial assets recorded at fair value which have been classified as either Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. Level 1 — Fair value based on quoted prices in active markets for identical assets or liabilities. Level 2 — Fair value based on inputs other than Level 1 inputs that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Fair value based on unobservable inputs that are supported by little or no market activity and such inputs are significant to the fair value of the assets or liabilities. The carrying amounts reflected in the Consolidated Balance Sheets for cash, cash equivalents, accounts receivable, accounts payable, and accrued expenses approximate fair value due to their short-term maturities.
Cash, Cash Equivalents, and Marketable Investments	Cash, Cash Equivalents, and Marketable Investments Forrester considers all short-term, highly liquid investments with original maturities at the time of purchase of 90 days or less to be cash equivalents. The Company’s portfolio of investments may at any time include securities of U.S. government agencies, municipal notes and bonds, corporate notes and bonds, commercial paper, and money market funds. Forrester accounts for all marketable investments as available-for-sale securities and as such, the marketable investments are carried at fair value with unrealized gains and losses (not related to credit losses) recorded in accumulated other comprehensive loss in the Consolidated Balance Sheets. Realized gains and losses on securities are included in earnings and are determined using the specific identification method. The Company conducts periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment and its application to certain investments, as required under current accounting standards. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in accumulated other comprehensive loss. The determination of whether a loss is considered temporary is based in part on whether the Company intends to sell the security or whether the Company would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. During the years ended December 31, 2017, 2016 and 2015, the Company did not record any other-than-temporary impairment losses on its available-for-sale securities.
Concentrations of Credit Risk	Concentrations of Credit Risk Forrester has no off-balance sheet or significant concentration of credit risk such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject Forrester to concentrations of credit risk are principally cash, cash equivalents, marketable investments, and accounts receivable. Forrester places its investments in highly rated securities. No single customer accounted for greater than 2% of revenues or 3% of accounts receivable in any of the periods presented.
Deferred Commissions	Deferred Commissions Commissions incurred in acquiring new or renewing existing contracts, which are earned in the month that a contract is booked, are deferred and expensed to operations as the related revenue is recognized. Forrester evaluates the recoverability of deferred commissions at each balance sheet date.
Goodwill	Goodwill Goodwill is not amortized; however, it is required to be tested for impairment annually. Furthermore, testing for impairment is required on an interim basis if an event or circumstance indicates that it is more likely than not an impairment loss has been incurred. An impairment loss would be recognized to the extent that the carrying amount of goodwill exceeds its implied fair value. Absent an event that indicates a specific impairment may exist, the Company has selected November 30th as the date for performing the annual goodwill impairment test. Goodwill impairment charges have not been required for the years ended December 31, 2017, 2016 and 2015.
Impairment of Other Long-Lived Tangible and Intangible Assets	Impairment of Other Long-Lived Tangible and Intangible Assets Forrester continually evaluates whether events or circumstances have occurred that indicate that the estimated remaining useful life of long-lived assets and intangible assets may warrant revision or if events or circumstances indicate that the carrying value of these assets may be impaired. To compute whether assets have been impaired, the estimated undiscounted future cash flows for the estimated remaining useful life of the assets are compared to the carrying value. To the extent that the future cash flows are less than the carrying value, the assets are written down to the estimated fair value of the asset. Impairment charges have not been required for the years ended December 31, 2017, 2016 and 2015.
Non-Current Liabilities	Non-Current Liabilities The Company records certain liabilities that are expected to be settled over a period that exceeds one year as non-current liabilities. The Company also records as a non-current liability the portion of the deferred rent liability that is expected to be recognized over a period greater than one year. The non-current deferred rent liability at December 31, 2017 and 2016 was $7.5 million and $7.4 million, respectively, and results from the difference between cash payments and the straight-line recognition of rent expense under the Company’s facility leases.
Foreign Currency	Foreign Currency The functional currency of the majority of Forrester’s wholly-owned subsidiaries is their respective local currency. These subsidiary financial statements are translated to U.S. dollars using period-end exchange rates for assets and liabilities and average exchange rates during the corresponding period for revenues and expenses, with translation gains and losses accumulated as a component of accumulated other comprehensive loss in the Consolidated Balance Sheets. Gains and losses related to the remeasurement of monetary assets and liabilities denominated in a currency other than an entity’s functional currency are included in other income, net in the Consolidated Statements of Income. For the years ended December 31, 2017 and 2016, Forrester recorded $0.6 million of foreign exchange losses and $0.1 million of foreign exchange gains, respectively, in other income, net. Foreign exchange losses were insignificant for the year ended December 31, 2015.
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The components of accumulated other comprehensive income (loss) are as follows (in thousands): Total Net Unrealized Gain Cumulative Accumulated (Loss) on Marketable Translation Other Comprehensive Investments Adjustment Income (Loss) Balance at December 31, 2014 $ (74 ) $ (1,539 ) $ (1,613 ) Foreign currency translation before reclassification — (3,505 ) (3,505 ) Reclassification adjustment for write-off of foreign currency translation loss — 318 318 Unrealized loss on investments, net of tax of $20 (26 ) — (26 ) Balance at December 31, 2015 (100 ) (4,726 ) (4,826 ) Foreign currency translation — (2,764 ) (2,764 ) Unrealized gain on investments, net of tax of ($14) 17 — 17 Balance at December 31, 2016 (83 ) (7,490 ) (7,573 ) Foreign currency translation — 5,593 5,593 Unrealized loss on investments, net of tax of $22 (32 ) — (32 ) Balance at December 31, 2017 $ (115 ) $ (1,897 ) $ (2,012 ) The reclassification adjustment for the write-off of a foreign currency translation loss relates to the liquidation of a non-U.S. subsidiary during 2015 and is reported in reorganization costs in the Consolidated Statements of Income.
Revenue Recognition	Revenue Recognition Forrester generates revenues from memberships to, and sales of, its Research, Connect and Analytics (rebranded from Data) products, performing advisory services and consulting projects and hosting Events. Forrester executes contracts that govern the terms and conditions of each arrangement. Revenues are recognized when persuasive evidence of an arrangement exists, the fee is fixed or determinable, services have been provided to the customer, and collectability is reasonably assured. Revenues are presented net of any sales or value added taxes that are collected from customers and remitted to the government. Revenue contracts may include either a single product or service or a combination of multiple products and services. Revenues from contracts that contain multiple products and services are allocated among the separate units of accounting based on their relative selling prices; however, the amount recognized is limited to the amount that is not contingent on future performance conditions. The Company obtains the relative selling prices of its products and services based on an analysis of standalone sales of these products and services during the year or upon an analysis of the estimated selling price of products for which there are insufficient standalone sales. The majority of research services revenues, including Research, Leadership Boards and the Analytics subscription products, are recognized ratably over the term of the contract. Research services revenues such as reprints are recognized as revenue when delivered. Advisory services revenues, such as workshops, speeches and advisory days, are recognized when the customer receives the agreed upon deliverable and consulting project revenues, which are short-term in nature and based upon fixed-fee agreements, are recognized as the services are provided. Event revenues are recognized upon completion of the Event. Reimbursed out-of-pocket expenses are recorded as advisory services and events revenue. Annual subscriptions to our Research include 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 and are accounted for as one unit of accounting. Annual subscriptions for Leadership Boards include 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. Leadership Boards are accounted for as two units of accounting: (1) the Event ticket and (2) the remaining services that are delivered throughout the contract period. Arrangement consideration is allocated to each of these elements based upon their relative selling prices, which is based on standalone sales of Event tickets and the estimated selling price of the remaining services. Annual subscriptions to our Analytics subscription products include access to designated survey data products and access to a data advisor, which are delivered throughout the contract period, and are accounted for as one unit of accounting and recognized ratably as research services revenue over the contract period. Certain of the Analytics subscription products also include advisory services and these contracts are accounted for as two units of accounting: (1) the subscription and data advisor and (2) the advisory services. Arrangement consideration is allocated to each element based upon its relative selling price, which is determined based on standalone sales of the advisory services and the estimated selling price of the remaining Analytics services.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes the fair value of stock-based compensation expense over the requisite service period of the individual grantee, which generally equals the vesting period. The Company adopted the guidance in Accounting Standards Update ("ASU") No. 2016-09, Compensation - Stock Compensation Improvements to Employee Share-Based Payment Accounting Additionally, ASU No. 2016-09 requires that all income tax effects related to settlements of share-based payment awards be reported in earnings as an increase or decrease to income tax expense. Previously, income tax benefits at settlement of an award were reported as an increase (or decrease) to additional paid-in capital to the extent that those benefits were greater than (or less than) the income tax benefits reported in earnings during the award's vesting period. The requirement to report those income tax effects in earnings has been applied on a prospective basis to settlements occurring on or after January 1, 2017, and the impact of applying this guidance resulting in a $0.4 million decrease to income tax expense in the consolidated financial statements for the year ended December 31, 2017. ASU No. 2016-09 also requires that all income tax-related cash flows resulting from share-based payments be reported as operating activities in the statement of cash flows. Previously, income tax benefits at settlement of an award were reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award's vesting period. In addition, the standard requires that cash paid by directly withholding shares for tax withholding purposes be classified as a financing activity in the statement of cash flows. For the year ended December 31, 2017, the Company reflected $2.5 million of tax withholding in financing activities. The Company has elected to apply the changes in cash flow classification on a retrospective basis, resulting in an increase in operating cash flows, with a corresponding decrease in financing cash flows, of approximately $2.6 million and $1.5 million for the years ended December 31, 2016 and 2015, respectively, as compared to the amounts previously reported. Stock-based compensation expense was recorded in the following expense categories (in thousands): Years Ended December 31, 2017 2016 2015 Cost of services and fulfillment $ 4,538 $ 4,431 $ 4,573 Selling and marketing 717 1,054 1,152 General and administrative 3,235 2,491 2,622 Total $ 8,490 $ 7,976 $ 8,347 The options granted under the equity incentive plan and shares subject to the employee stock purchase plan were valued utilizing the Black-Scholes model using the following assumptions and had the following fair values (no options were granted in 2017): Years Ended December 31, 2017 2016 2015 Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Average risk-free interest rate 0.90 % 1.30 % 0.32 % 1.59 % 0.07 % Expected dividend yield 1.9 % 2.2 % 2.1 % 2.1 % 1.9 % Expected life 0.5 Years 5.0 Years 0.5 Years 5.0 Years 0.5 Years Expected volatility 24 % 24 % 24 % 24 % 22 % Weighted average fair value $ 8.36 $ 6.16 $ 6.69 $ 6.15 $ 7.19 Dividend yields are based on the initiation of a regular quarterly dividend program approved by the Board of Directors in February 2012. Expected volatility is based, in part, on the historical volatility of Forrester’s common stock as well as management’s expectations of future volatility over the expected term of the awards granted. The risk-free interest rate is based on the U.S. Treasury Constant Maturity rate with an equivalent remaining term. Where the expected term of a stock-based award does not correspond with a term for which the interest rates are quoted, Forrester uses the rate with the maturity closest to the award’s expected term. The expected term calculation is based upon Forrester’s historical experience of exercise patterns. The unamortized fair value of stock-based awards as of December 31, 2017 was $16.6 million, with a weighted average remaining recognition period of 2.6 years.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts Forrester maintains an allowance for doubtful accounts for estimated losses resulting from the inability of its customers to make contractually obligated payments. When evaluating the adequacy of the allowance for doubtful accounts, the Company makes judgments regarding the collectability of accounts receivable by specifically analyzing historical bad debts, customer concentrations, current economic trends, and changes in the customer payment terms. If the financial condition of the Company’s customers were to deteriorate, resulting in an impairment of their ability to make payments, additional allowances may be required and if the financial condition of the Company’s customers were to improve, the allowances may be reduced accordingly.
Depreciation and Amortization	Depreciation and Amortization Forrester provides for depreciation and amortization of property and equipment, computed using the straight-line method, over estimated useful lives of assets as follows: Estimated Useful Life Computers and equipment 3 to 10 Years Computer software 3 to 5 Years Furniture and fixtures 7 Years Leasehold improvements Shorter of asset life or lease term Forrester provides for amortization of intangible assets, computed using an accelerated method according to the expected cash flows to be received from the underlying assets, over the respective lives as follows: Estimated Useful Life Customer relationships 5 to 11 Years Research content 1 to 2 Years Technology 7 Years
Income Taxes	Income Taxes Forrester recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statements and tax basis of assets and liabilities as well as operating loss carryforwards. Forrester’s provision for income taxes is composed of a current and a deferred provision for federal, state and foreign jurisdictions. The current provision is calculated as the estimated taxes payable or refundable on tax returns for the current year. The deferred income tax provision is calculated as the net change during the year in deferred tax assets and liabilities. Valuation allowances are provided if based on the weight of available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. Forrester accounts for uncertain tax positions using a “more-likely-than-not” threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity, and changes in facts or circumstances related to a tax position. The Company evaluates these tax positions on a quarterly basis. The Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense. The Company elected to early adopt the guidance in ASU No. 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory
Net Income Per Common Share	Net Income Per Common Share Basic net income per common share is computed by dividing net income by the basic weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the diluted weighted average number of common shares and common equivalent shares outstanding during the period. The weighted average number of common equivalent shares outstanding has been determined in accordance with the treasury-stock method. Common stock equivalents consist of common stock issuable upon the exercise of outstanding stock options and the vesting of restricted stock units. Basic and diluted weighted average common shares are as follows (in thousands): Years Ended December 31, 2017 2016 2015 Basic weighted average common shares outstanding 17,919 17,984 17,927 Weighted average common equivalent shares 321 285 216 Diluted weighted average common shares outstanding 18,240 18,269 18,143 Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive 133 706 1,237
New Accounting Pronouncements	New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers: Principal versus Agent Considerations Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing , Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients Technical Corrections and Improvements: Revenue from Contracts with Customers The new standard will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company will adopt the standard as of January 1, 2018 utilizing the modified retrospective method. The Company does not anticipate that the standard will have a material impact on its results of operations. The number of performance obligations in the Company’s arrangements will not be different under the new standard. Determining standalone selling prices and allocating contract consideration on multiple element arrangements will not be different from the Company’s current methodologies of establishing fair value and estimated selling price for our goods and services or allocating total contract consideration under the relative selling price method. Additionally, the timing of revenue recognition will remain substantially unchanged for most products. Subscription based research services revenues will continue to be recognized over time, using the new standard’s output method of time elapsed, as Forrester’s clients receive and consume the benefits of its services as the Company transfers control throughout the contract period. Advisory, reprint and Events revenues will continue to be recognized at the point in time as control is transferred to the customer, which will generally be when the client has physical possession of the good(s) or upon completion of the service(s). The Company expects that most of its consulting contracts will continue to be recognized over time, while some contracts may be required to be recognized at a point in time upon completion of the project. The following changes are anticipated under the new standard: • The Company will no longer record accounts receivable and deferred revenue on its balance sheet when it issues an invoice to a customer for a contract that is cancellable by the customer. For contracts that are cancellable, the Company will only record accounts receivable up to the amount of revenue earned but not yet collected. This change will have the effect of reducing the amount of accounts receivable and deferred revenue on the balance sheet compared to amounts recorded based on current accounting standards. The majority of the Company’s contracts are non-cancellable; however, the Company has not yet determined the effect of this change on its balance sheet. • The timing of revenue recognition for prepaid performance obligations that are expected to expire unused, which may include Event tickets, reprints and advisory hours, will change from recognition at the time of expiration under the current standard to recognition in proportion to the pattern of related rights exercised by the customer. The Company currently expects this change to primarily affect the timing of revenue within the quarters of 2018 but does not expect it to have a material effect on the Company’s results of operations for the full year of 2018. • Costs to fulfill contracts, such as our survey costs for our Analtyics product line, are currently deferred and recognized over the aggregate period of the contracts under the current standards. These costs will be recognized as incurred under the new standard, which the Company expects will have an immaterial effect on the results of operations for the full year of 2018, however it will change the timing of the recognition of the costs on a quarterly basis as compared to the current standards. Key areas still in process include the calculation of the cumulative effect adjustment for the adoption of the standard, which will be recorded as of January 1, 2018, and development of reports for the various disclosures required in 2018. These areas will be completed by the end of the first quarter of 2018. In February 2016, the FASB issued ASU No. 2016-02, Leases In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other: Simplifying the Test for Goodwill Impairment

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Components of Accumulated Other Comprehensive Income (Loss)	The components of accumulated other comprehensive income (loss) are as follows (in thousands): Total Net Unrealized Gain Cumulative Accumulated (Loss) on Marketable Translation Other Comprehensive Investments Adjustment Income (Loss) Balance at December 31, 2014 $ (74 ) $ (1,539 ) $ (1,613 ) Foreign currency translation before reclassification — (3,505 ) (3,505 ) Reclassification adjustment for write-off of foreign currency translation loss — 318 318 Unrealized loss on investments, net of tax of $20 (26 ) — (26 ) Balance at December 31, 2015 (100 ) (4,726 ) (4,826 ) Foreign currency translation — (2,764 ) (2,764 ) Unrealized gain on investments, net of tax of ($14) 17 — 17 Balance at December 31, 2016 (83 ) (7,490 ) (7,573 ) Foreign currency translation — 5,593 5,593 Unrealized loss on investments, net of tax of $22 (32 ) — (32 ) Balance at December 31, 2017 $ (115 ) $ (1,897 ) $ (2,012 )
Summary of Stock-Based Compensation Expense Recorded in Expense Categories	Stock-based compensation expense was recorded in the following expense categories (in thousands): Years Ended December 31, 2017 2016 2015 Cost of services and fulfillment $ 4,538 $ 4,431 $ 4,573 Selling and marketing 717 1,054 1,152 General and administrative 3,235 2,491 2,622 Total $ 8,490 $ 7,976 $ 8,347
Options Granted Under Equity Incentive Plans and Shares Subject to Employee Stock Purchase Plan Valuation Assumptions	The options granted under the equity incentive plan and shares subject to the employee stock purchase plan were valued utilizing the Black-Scholes model using the following assumptions and had the following fair values (no options were granted in 2017): Years Ended December 31, 2017 2016 2015 Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Equity Incentive Plans Employee Stock Purchase Plan Average risk-free interest rate 0.90 % 1.30 % 0.32 % 1.59 % 0.07 % Expected dividend yield 1.9 % 2.2 % 2.1 % 2.1 % 1.9 % Expected life 0.5 Years 5.0 Years 0.5 Years 5.0 Years 0.5 Years Expected volatility 24 % 24 % 24 % 24 % 22 % Weighted average fair value $ 8.36 $ 6.16 $ 6.69 $ 6.15 $ 7.19
Depreciation and Amortization of Property and Equipment, Useful Life	Forrester provides for depreciation and amortization of property and equipment, computed using the straight-line method, over estimated useful lives of assets as follows: Estimated Useful Life Computers and equipment 3 to 10 Years Computer software 3 to 5 Years Furniture and fixtures 7 Years Leasehold improvements Shorter of asset life or lease term
Amortization of Intangible Assets, Useful Life	Forrester provides for amortization of intangible assets, computed using an accelerated method according to the expected cash flows to be received from the underlying assets, over the respective lives as follows: Estimated Useful Life Customer relationships 5 to 11 Years Research content 1 to 2 Years Technology 7 Years
Schedule of Basic and Diluted Weighted Average Common Shares	Basic and diluted weighted average common shares are as follows (in thousands): Years Ended December 31, 2017 2016 2015 Basic weighted average common shares outstanding 17,919 17,984 17,927 Weighted average common equivalent shares 321 285 216 Diluted weighted average common shares outstanding 18,240 18,269 18,143 Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive 133 706 1,237

Goodwill and Other Intangible22

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Goodwill by Segment and Changes in Carrying Amount of Goodwill	A summary of the goodwill by segment and the changes in the carrying amount of goodwill is shown in the following table (in thousands). Project Product Research Consulting Total Balance at January 1, 2016 $ 2,371 $ 71,700 $ — $ 74,071 Translation adjustments (28 ) (850 ) — (878 ) Balance at December 31, 2016 2,343 70,850 — 73,193 Translation adjustments 95 2,881 — 2,976 Balance at December 31, 2017 $ 2,438 $ 73,731 $ — $ 76,169
Summary of Intangible Assets	A summary of Forrester’s intangible assets is as follows (in thousands): December 31, 2017 Gross Net Carrying Accumulated Carrying Amount Amortization Amount Amortizable intangible assets: Customer relationships $ 31,735 $ 31,003 $ 732 Research content 1,083 1,083 — Total $ 32,818 $ 32,086 $ 732 December 31, 2016 Gross Net Carrying Accumulated Carrying Amount Amortization Amount Amortizable intangible assets: Customer relationships $ 30,998 $ 29,534 $ 1,464 Research content 1,083 1,083 — Total $ 32,081 $ 30,617 $ 1,464

Marketable Investments (Tables)

Marketable Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Summary of Company's Marketable Investments	The following table summarizes the Company’s marketable investments, all of which are classified as available-for-sale (in thousands): As of December 31, 2017 Gross Gross Amortized Unrealized Unrealized Market Cost Gains Losses Value Federal agency obligations $ 1,800 $ — $ (7 ) $ 1,793 Corporate obligations 52,721 — (181 ) 52,540 Total $ 54,521 $ — $ (188 ) $ 54,333 As of December 31, 2016 Gross Gross Amortized Unrealized Unrealized Market Cost Gains Losses Value Federal agency obligations $ 1,800 $ — $ (7 ) $ 1,793 Corporate obligations 59,481 2 (129 ) 59,354 Total $ 61,281 $ 2 $ (136 ) $ 61,147
Summary of Maturity Periods of Marketable Investments	The following table summarizes the maturity periods of the marketable investments in the Company’s portfolio as of December 31, 2017. FY 2018 FY 2019 Total Federal agency obligations $ 1,793 $ — $ 1,793 Corporate obligations 31,494 21,046 52,540 Total $ 33,287 $ 21,046 $ 54,333
Summary of Gross Unrealized Losses and Market Value of Available-for-Sale Securities with Unrealized Losses	The following table shows the gross unrealized losses and market value of Forrester’s available-for-sale securities with unrealized losses that are not deemed to be other-than-temporary, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands): As of December 31, 2017 Less Than 12 Months 12 Months or Greater Market Unrealized Market Unrealized Value Losses Value Losses Federal agency obligations $ — $ — $ 1,793 $ 7 Corporate obligations 31,723 149 20,817 32 Total $ 31,723 $ 149 $ 22,610 $ 39 As of December 31, 2016 Less Than 12 Months 12 Months or Greater Market Unrealized Market Unrealized Value Losses Value Losses Federal agency obligations $ 1,793 $ 7 $ — $ — Corporate obligations 53,647 129 — — Total $ 55,440 $ 136 $ — $ —
Summary of Company's Fair Value Hierarchy for its Financial Assets	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and marketable investments) measured at fair value on a recurring basis (in thousands): As of December 31, 2017 Level 1 Level 2 Level 3 Total Money market funds (1) $ 492 $ — $ — $ 492 Federal agency obligations — 1,793 — 1,793 Corporate obligations — 52,540 — 52,540 Total $ 492 $ 54,333 $ — $ 54,825 As of December 31, 2016 Level 1 Level 2 Level 3 Total Money market funds (1) $ 2,522 $ — $ — $ 2,522 Federal agency obligations — 1,793 — $ 1,793 Corporate obligations — 59,354 — 59,354 Total $ 2,522 $ 61,147 $ — $ 63,669 (1) Included in cash and cash equivalents.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Before Income Taxes	Income before income taxes consists of the following (in thousands): Years Ended December 31, 2017 2016 2015 Domestic $ 20,061 $ 22,303 $ 11,347 Foreign 7,310 8,406 7,973 Total $ 27,371 $ 30,709 $ 19,320
Components of the Income Tax Provision (benefit)	The components of the income tax provision (benefit) are as follows (in thousands): Years Ended December 31, 2017 2016 2015 Current: Federal $ 2,587 $ 6,094 $ 5,103 State 1,060 2,330 1,252 Foreign 2,159 2,032 1,954 Total current 5,806 10,456 8,309 Deferred: Federal 5,550 2,719 (723 ) State 700 59 (232 ) Foreign 175 (176 ) (30 ) Total deferred 6,425 2,602 (985 ) Income tax provision $ 12,231 $ 13,058 $ 7,324
Reconciliation of the Federal Statutory Rate	A reconciliation of the federal statutory rate to Forrester’s effective tax rate is as follows: Years Ended December 31, 2017 2016 2015 Income tax provision at federal statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in tax resulting from: State tax provision, net of federal benefit 4.0 5.0 4.0 Foreign tax rate differential (3.4 ) (4.4 ) (3.0 ) Stock option compensation deduction 0.1 0.6 2.5 Withholding taxes 1.7 0.5 0.3 Non-deductible expenses 1.8 1.5 1.7 Change in valuation allowance 3.9 3.2 (0.7 ) Change in tax legislation 5.8 — (3.1 ) Audit settlements (4.0 ) — — Other, net (0.2 ) 1.1 1.2 Effective tax rate 44.7 % 42.5 % 37.9 %
Components of Deferred Income Taxes	The components of deferred income taxes are as follows (in thousands): As of December 31, 2017 2016 Non-deductible reserves and accruals $ 4,936 $ 8,189 Net operating loss and other carryforwards 8,528 7,560 Stock compensation 2,644 5,327 Depreciation and amortization 402 1,196 Other assets 46 50 Gross deferred tax asset 16,556 22,322 Less - valuation allowance (2,686 ) (2,193 ) Sub-total 13,870 20,129 Other liabilities (911 ) (453 ) Goodwill amortization (5,677 ) (5,013 ) Deferred commissions (3,873 ) (4,928 ) Net deferred tax asset $ 3,409 $ 9,735
Summary of Changes in Deferred Tax Valuation Allowance	The following table provides a summary of the changes in the deferred tax valuation allowance for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Deferred tax valuation allowance at January 1 $ 2,193 $ 1,534 $ 1,565 Additions 1,439 1,256 150 Deductions (70 ) (455 ) (134 ) Change in tax legislation (954 ) — — Translation adjustments 78 (142 ) (47 ) Deferred tax valuation allowance at December 31 $ 2,686 $ 2,193 $ 1,534
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is summarized as follows for the years ended December 31, 2017, 2016 and 2015 (in thousands): 2017 2016 2015 Unrecognized tax benefits at January 1 $ 1,774 $ 1,910 $ 2,136 Additions for tax positions of prior years — — 36 Reductions for tax positions of prior years — (31 ) — Additions for tax positions of current year — 75 46 Settlements (986 ) (163 ) (303 ) Lapse of statute of limitations — — — Translation adjustments 18 (17 ) (5 ) Unrecognized tax benefits at December 31 $ 806 $ 1,774 $ 1,910

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Future Contractual Obligations for Operating Leases	As of December 31, 2017, Forrester had future contractual obligations as follows for operating leases (in thousands): 2018 $ 12,506 2019 11,442 2020 10,835 2021 9,409 2022 8,001 Thereafter 29,490 Total minimum lease payments $ 81,683

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Restricted Stock Unit Activity	RSU activity for the year ended December 31, 2017 is presented below (in thousands, except per share data): Weighted- Average Number of Grant Date Shares Fair Value Unvested at December 31, 2016 539 $ 35.50 Granted 253 39.73 Vested (212 ) 35.38 Forfeited (71 ) 35.92 Unvested at December 31, 2017 509 $ 37.59
Schedule of Stock Option Activity	Stock option activity for the year ended December 31, 2017 is presented below (in thousands, except per share data and contractual term): Weighted - Weighted - Average Average Exercise Remaining Aggregate Number Price Per Contractual Intrinsic of Shares Share Term (in years) Value Outstanding at December 31, 2016 1,540 $ 34.35 Granted — — Exercised (512 ) 32.90 Forfeited (91 ) 34.87 Outstanding at December 31, 2017 937 $ 35.10 5.86 $ 8,529 Exercisable at December 31, 2017 650 $ 34.98 5.16 $ 5,992 Vested and expected to vest at December 31, 2017 937 $ 35.10 5.86 $ 8,529
Summary of Shares Purchased by Employees Under the Stock Purchase Plan	Shares purchased by employees under the Stock Purchase Plan are as follows (in thousands, except per share data): Shares Purchase Purchase Period Ended Purchased Price February 28, 2017 24 $ 31.03 August 31, 2017 26 $ 31.71 February 29, 2016 28 $ 26.00 August 31, 2016 25 $ 27.04

Reorganization (Tables)

Reorganization (Tables)	12 Months Ended
	Dec. 31, 2017
Restructuring And Related Activities [Abstract]
Schedule of Rolls Forward of Activity in Reorganization Accrual	The activity related to the reorganization accrual during the year ended December 31, 2016 is as follows (in thousands): Workforce Subsidiary Products Reduction Liquidation Reorganization Total Accrual at December 31, 2015 $ 41 $ 7 $ 433 $ 481 Additions 1,022 — 4 1,026 Cash payments (1,063 ) (7 ) (437 ) (1,507 ) Accrual at December 31, 2016 $ — $ — $ — $ —

Operating Segment and Enterpr28

Operating Segment and Enterprise Wide Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Information about Reportable Segments	The following tables present information about reportable segments (in thousands): Project Product Research Consulting Consolidated Year Ended December 31, 2017 Research services revenues $ 216,471 $ — $ — $ 216,471 Advisory services and events revenues 21,887 45,054 54,261 121,202 Total segment revenues 238,358 45,054 54,261 337,673 Segment expenses 45,205 48,812 25,477 119,494 Contribution margin (loss) 193,153 (3,758 ) 28,784 218,179 Selling, marketing, administrative and other expenses (189,849 ) Amortization of intangible assets (781 ) Reorganization costs — Other income and losses on investments (178 ) Income before income taxes $ 27,371 Project Product Research Consulting Consolidated Year Ended December 31, 2016 Research services revenues $ 215,216 $ — $ — $ 215,216 Advisory services and events revenues 20,374 44,631 45,874 110,879 Total segment revenues 235,590 44,631 45,874 326,095 Segment expenses 41,528 47,496 23,141 112,165 Contribution margin (loss) 194,062 (2,865 ) 22,733 213,930 Selling, marketing, administrative and other expenses (181,299 ) Amortization of intangible assets (831 ) Reorganization costs (1,026 ) Other income and losses on investments (65 ) Income before income taxes $ 30,709 Project Product Research Consulting Consolidated Year Ended December 31, 2015 Research services revenues $ 210,268 $ — $ — $ 210,268 Advisory services and events revenues 17,512 42,422 43,524 103,458 Total segment revenues 227,780 42,422 43,524 313,726 Segment expenses 38,615 48,277 23,292 110,184 Contribution margin (loss) 189,165 (5,855 ) 20,232 203,542 Selling, marketing, administrative and other expenses (179,391 ) Amortization of intangible assets (891 ) Reorganization costs (4,433 ) Other income and losses on investments 493 Income before income taxes $ 19,320
Schedule of Net Long-lived Tangible Assets by Location	Net long-lived tangible assets by location as of December 31, 2017 and 2016 are as follows (in thousands): 2017 2016 United States $ 23,943 $ 22,150 United Kingdom 727 782 Europe (excluding United Kingdom) 163 259 Other 416 703 Total $ 25,249 $ 23,894
Schedule of Revenues by Geographic Destination and as a Percentage of Total Revenues	Revenues by geographic destination and as a percentage of total revenues for the years ended December 31, 2017, 2016, and 2015 are as follows (dollars in thousands): 2017 2016 2015 United States $ 260,077 $ 252,222 $ 241,025 Europe (excluding United Kingdom) 28,525 27,061 24,607 United Kingdom 13,651 14,808 16,815 Canada 14,523 13,806 14,424 Other 20,897 18,198 16,855 Total $ 337,673 $ 326,095 $ 313,726 2017 2016 2015 United States 77 % 77 % 77 % Europe (excluding United Kingdom) 9 8 8 United Kingdom 4 5 5 Canada 4 4 5 Other 6 6 5 Total 100 % 100 % 100 %

Certain Balance Sheet Accounts

Certain Balance Sheet Accounts (Tables)	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Property and Equipment	Property and equipment as of December 31, 2017 and 2016 is recorded at cost less accumulated depreciation and consists of the following (in thousands): 2017 2016 Computers and equipment $ 18,570 $ 17,137 Computer software 29,891 26,686 Furniture and fixtures 9,094 8,471 Leasehold improvements 26,650 25,204 Total property and equipment 84,205 77,498 Less accumulated depreciation 58,956 53,604 Total $ 25,249 $ 23,894
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities as of December 31, 2017 and 2016 consist of the following (in thousands): 2017 2016 Payroll and related benefits $ 34,809 $ 28,681 Taxes 3,912 4,704 Other 10,908 8,018 Total $ 49,629 $ 41,403
Summary of Allowance for Doubtful Accounts	A roll-forward of the allowance for doubtful accounts as of and for the years ended December 31, 2017, 2016, and 2015 is as follows (in thousands): 2017 2016 2015 Balance, beginning of year $ 140 $ 153 $ 188 Provision for doubtful accounts 331 150 106 Write-offs (316 ) (163 ) (141 ) Balance, end of year $ 155 $ 140 $ 153

Summary Selected Quarterly Fi30

Summary Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of Selected Consolidated Quarterly Financial Data	The following is a summary of selected unaudited consolidated quarterly financial data for the years ended December 31, 2017 and 2016 (in thousands, except per share data): Three Months Ended March 31, June 30, September 30, December 31, 2017 2017 2017 2017 Total revenues $ 77,194 $ 89,733 $ 80,369 $ 90,377 Income from operations $ 3,136 $ 10,213 $ 6,749 $ 7,451 Net income $ 3,030 $ 6,064 $ 3,953 $ 2,093 Basic income per common share $ 0.17 $ 0.34 $ 0.22 $ 0.12 Diluted income per common share $ 0.16 $ 0.34 $ 0.22 $ 0.11 Three Months Ended March 31, June 30, September 30, December 31, 2016 2016 2016 2016 Total revenues $ 77,401 $ 87,821 $ 77,427 $ 83,446 Income from operations $ 2,712 $ 11,472 $ 7,552 $ 9,038 Net income $ 1,289 $ 7,460 $ 3,112 $ 5,790 Basic income per common share $ 0.07 $ 0.42 $ 0.17 $ 0.32 Diluted income per common share $ 0.07 $ 0.41 $ 0.17 $ 0.31

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)Customershares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Summary Of Significant Accounting Policy [Line Items]
Original maturities	90 days
Number of customers accounted for revenues or accounts receivable greater than 2% or 3% of total | Customer	0
Annual goodwill impairment test, period	November 30th
Goodwill impairment charges	$ 0	$ 0	$ 0
Non-current deferred rent liabilities	7,500,000	7,400,000
Foreign exchange gains (losses)	(600,000)	100,000
Tax withholding in financing activities	$ 2,527,000	2,069,000	1,459,000
Options granted | shares	0
Unamortized fair value stock based compensation	$ 16,600,000
Weighted average remaining recognition period	2 years 7 months 6 days
ASU No. 2016-09 [Member]
Summary Of Significant Accounting Policy [Line Items]
Cumulative effect adjustment to increase or (reduce) retained earnings		200,000
Decrease to income tax expense	$ 400,000
Tax withholding in financing activities	$ 2,500,000
Change in reclassification of tax withholding		2,600,000	$ 1,500,000
Early Adoption of ASU No. 2016-16 [Member]
Summary Of Significant Accounting Policy [Line Items]
Cumulative effect adjustment to increase or (reduce) retained earnings		$ (500,000)
Research Service Revenue [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policy [Line Items]
Customer accounted for percentage	2.00%
Accounts Receivable [Member] | Credit Concentration Risk [Member]
Summary Of Significant Accounting Policy [Line Items]
Customer accounted for percentage	3.00%

Summary of Significant Accoun32

Summary of Significant Accounting Policies - Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (7,573)
Foreign currency translation before reclassification			$ (3,505)
Foreign currency translation	5,593	$ (2,764)	(3,187)
Reclassification adjustment for write-off of foreign currency translation loss			318
Unrealized gain (loss) on investments, net of tax	(32)	17	(26)
Ending Balance	(2,012)	(7,573)
Beginning Balance	150,036	127,302	141,602
Ending Balance	141,189	150,036	127,302
Net Unrealized Gain (Loss) on Marketable Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(83)	(100)	(74)
Unrealized gain (loss) on investments, net of tax	(32)	17	(26)
Ending Balance	(115)	(83)	(100)
Cumulative Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7,490)	(4,726)	(1,539)
Foreign currency translation before reclassification			(3,505)
Foreign currency translation	5,593	(2,764)
Reclassification adjustment for write-off of foreign currency translation loss			318
Ending Balance	(1,897)	(7,490)	(4,726)
Total Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation	5,593	(2,764)	(3,187)
Beginning Balance	(7,573)	(4,826)	(1,613)
Ending Balance	$ (2,012)	$ (7,573)	$ (4,826)

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Comprehensive Income Loss Tax Parenthetical Disclosures [Abstract]
Tax on Unrealized gain (loss) on investments before reclassification	$ 22	$ (14)	$ 20

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Summary of Stock-Based Compensation Expense Recorded in Expense Categories (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	$ 8,490	$ 7,976	$ 8,347
Cost of Services and Fulfillment [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	4,538	4,431	4,573
Selling and Marketing [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	717	1,054	1,152
General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total allocated share-based compensation expense	$ 3,235	$ 2,491	$ 2,622

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Options Granted Under Equity Incentive Plans and Shares Subject to Employee Stock Purchase Plan Valuation Assumptions (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average risk-free interest rate		1.30%	1.59%
Expected dividend yield		2.20%	2.10%
Expected life		5 years	5 years
Expected volatility		24.00%	24.00%
Weighted average fair value		$ 6.16	$ 6.15
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average risk-free interest rate	0.90%	0.32%	0.07%
Expected dividend yield	1.90%	2.10%	1.90%
Expected life	6 months	6 months	6 months
Expected volatility	24.00%	24.00%	22.00%
Weighted average fair value	$ 8.36	$ 6.69	$ 7.19

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Depreciation and Amortization of Property and Equipment, Useful Life (Detail)	12 Months Ended
	Dec. 31, 2017
Computers and Equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	3 years
Computers and Equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	10 years
Computer Software [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	3 years
Computer Software [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	5 years
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	7 years
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	Shorter of asset life or lease term

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Amortization of Intangible Assets, Useful Life (Detail)	12 Months Ended
	Dec. 31, 2017
Customer Relationships [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets, estimated useful life	5 years
Customer Relationships [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets, estimated useful life	11 years
Research Content [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets, estimated useful life	1 year
Research Content [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets, estimated useful life	2 years
Technology [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of intangible assets, estimated useful life	7 years

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Summary of Basic and Diluted Weighted Average Common Shares (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	17,919	17,984	17,927
Weighted average common equivalent shares	321	285	216
Diluted weighted average common shares outstanding	18,240	18,269	18,143
Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive	133	706	1,237

Goodwill and Other Intangible39

Goodwill and Other Intangible Assets - Summary of Goodwill by Segment and Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 73,193	$ 74,071
Translation adjustments	2,976	(878)
Goodwill, Ending Balance	76,169	73,193
Product Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	2,343	2,371
Translation adjustments	95	(28)
Goodwill, Ending Balance	2,438	2,343
Research Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	70,850	71,700
Translation adjustments	2,881	(850)
Goodwill, Ending Balance	$ 73,731	$ 70,850

Goodwill and Other Intangible40

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Accumulated goodwill impairment losses	$ 0
Amortization of intangible assets	781,000	$ 831,000	$ 891,000
Remaining net book value	$ 732,000	$ 1,464,000

Goodwill and Other Intangible41

Goodwill and Other Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 32,818	$ 32,081
Accumulated Amortization	32,086	30,617
Total	732	1,464
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	31,735	30,998
Accumulated Amortization	31,003	29,534
Total	732	1,464
Research Content [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,083	1,083
Accumulated Amortization	$ 1,083	$ 1,083

Marketable Investments - Summar

Marketable Investments - Summary of Company's Marketable Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 54,521	$ 61,281
Gross Unrealized Gains		2
Gross Unrealized Losses	(188)	(136)
Market Value	54,333	61,147
Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,800	1,800
Gross Unrealized Losses	(7)	(7)
Market Value	1,793	1,793
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	52,721	59,481
Gross Unrealized Gains		2
Gross Unrealized Losses	(181)	(129)
Market Value	$ 52,540	$ 59,354

Marketable Investments - Summ43

Marketable Investments - Summary of Maturity Periods of the Marketable Investments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
FY 2,018	$ 33,287
FY 2,019	21,046
Total	54,333	$ 61,147
Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
FY 2,018	1,793
Total	1,793	1,793
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
FY 2,018	31,494
FY 2,019	21,046
Total	$ 52,540	$ 59,354

Marketable Investments - Summ44

Marketable Investments - Summary of Gross Unrealized Losses and Market Value of Available-for-Sale Securities with Unrealized Losses (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, Less Than 12 Months, Market Value	$ 31,723	$ 55,440
Available for sale securities, Less Than 12 Months, Unrealized Losses	149	136
Available for sale securities, 12 Months or Greater, Market Value	22,610
Available for sale securities, 12 Months or Greater, Unrealized Losses	39
Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, Less Than 12 Months, Market Value		1,793
Available for sale securities, Less Than 12 Months, Unrealized Losses		7
Available for sale securities, 12 Months or Greater, Market Value	1,793
Available for sale securities, 12 Months or Greater, Unrealized Losses	7
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, Less Than 12 Months, Market Value	31,723	53,647
Available for sale securities, Less Than 12 Months, Unrealized Losses	149	$ 129
Available for sale securities, 12 Months or Greater, Market Value	20,817
Available for sale securities, 12 Months or Greater, Unrealized Losses	$ 32

Marketable Investments - Summ45

Marketable Investments - Summary of Company's Fair Value Hierarchy for its Financial Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	$ 54,825	$ 63,669
Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	492	2,522
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	492	2,522
Level 1 [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	492	2,522
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	54,333	61,147
Federal Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	1,793	1,793
Federal Agency Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	1,793	1,793
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	52,540	59,354
Corporate Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets on recurring basis	$ 52,540	$ 59,354

Non-Marketable Investments - Ad

Non-Marketable Investments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Investments Entities That Calculate Net Asset Value Per Share [Line Items]
Carrying value of the Company's non-marketable investments	$ 1,900,000	$ 2,800,000
Book value of investment		400,000
Losses from non-marketable investments	(500,000)	(800,000)
Distributions received from funds	$ 400,000	$ 0	$ 100,000
Limited Partnerships Investments [Member] | Minimum [Member]
Fair Value Investments Entities That Calculate Net Asset Value Per Share [Line Items]
Ownership interest of Company	5.00%

Income Taxes - Income Before In

Income Taxes - Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Domestic	$ 20,061	$ 22,303	$ 11,347
Foreign	7,310	8,406	7,973
Income before income taxes	$ 27,371	$ 30,709	$ 19,320

Income Taxes - Components of th

Income Taxes - Components of the Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 2,587	$ 6,094	$ 5,103
State	1,060	2,330	1,252
Foreign	2,159	2,032	1,954
Total current	5,806	10,456	8,309
Deferred:
Federal	5,550	2,719	(723)
State	700	59	(232)
Foreign	175	(176)	(30)
Total deferred	6,425	2,602	(985)
Income tax provision	$ 12,231	$ 13,058	$ 7,324

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax provision at federal statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in tax resulting from:
State tax provision, net of federal benefit	4.00%	5.00%	4.00%
Foreign tax rate differential	(3.40%)	(4.40%)	(3.00%)
Stock option compensation deduction	0.10%	0.60%	2.50%
Withholding taxes	1.70%	0.50%	0.30%
Non-deductible expenses	1.80%	1.50%	1.70%
Change in valuation allowance	3.90%	3.20%	(0.70%)
Change in tax legislation	5.80%		(3.10%)
Audit settlements	(4.00%)
Other, net	(0.20%)	1.10%	1.20%
Effective tax rate	44.70%	42.50%	37.90%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Income tax provision at federal statutory rate			35.00%	35.00%	35.00%
Additional income tax expense due to tax cuts and jobs act of 2017	$ 1,600,000
Provisional amount related to the remeasurement of federal deferred tax assets and liabilities			$ 1,200,000
Provisional amount related to one-time transition tax on mandatory deemed repatriation of foreign earnings			400,000
Cumulative foreign earnings from tax cuts and jobs act of 2017			$ 22,600,000
Tax Cuts and Jobs Act of 2017, accounting complete			false
Income tax benefit from new interpretation of tax law					$ 600,000
Long-term net deferred tax assets	3,500,000		$ 3,500,000	$ 9,800,000
Long-term net deferred tax liabilities	100,000		100,000	100,000
Valuation allowance	2,686,000		2,686,000	2,193,000	1,534,000	$ 1,565,000
Operating loss carryforwards related to a prior acquisition	3,600,000		3,600,000
U.S. federal and state capital loss carryforwards	6,600,000		6,600,000
Deferred tax assets, Capital loss carryforwards expires in 2018	400,000		400,000
Deferred tax assets, Capital loss carryforwards expires in 2020	1,600,000		1,600,000
Deferred tax assets, Capital loss carryforwards expires in 2021	1,400,000		1,400,000
Deferred tax assets, Capital loss carryforwards expires in 2022	3,200,000		3,200,000
Unremitted earnings of U.S. deferred tax liability of foreign subsidiaries	0		0
Unrecognized tax benefits	806,000		806,000	1,774,000	1,910,000	$ 2,136,000
Unrecognized tax benefits that may be settled within next twelve months	400,000		400,000
Accrued interest and penalties related to uncertain tax positions				$ 100,000	$ 200,000
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Operating loss carryforwards	$ 22,400,000		$ 22,400,000
Scenario, Forecast [Member]
Income Taxes [Line Items]
Income tax provision at federal statutory rate		21.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Non-deductible reserves and accruals	$ 4,936	$ 8,189
Net operating loss and other carryforwards	8,528	7,560
Stock compensation	2,644	5,327
Depreciation and amortization	402	1,196
Other assets	46	50
Gross deferred tax asset	16,556	22,322
Less - valuation allowance	(2,686)	(2,193)	$ (1,534)	$ (1,565)
Sub-total	13,870	20,129
Other liabilities	(911)	(453)
Goodwill amortization	(5,677)	(5,013)
Deferred commissions	(3,873)	(4,928)
Net deferred tax asset	$ 3,409	$ 9,735

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes in Deferred Tax Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Deferred tax valuation allowance, Beginning Balance	$ 2,193	$ 1,534	$ 1,565
Additions	1,439	1,256	150
Deductions	(70)	(455)	(134)
Change in tax legislation	(954)
Translation adjustments	78	(142)	(47)
Deferred tax valuation allowance, Ending Balance	$ 2,686	$ 2,193	$ 1,534

Income Taxes - Reconciliation53

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, Beginning Balance	$ 1,774	$ 1,910	$ 2,136
Additions for tax positions of prior years			36
Reductions for tax positions of prior years		(31)
Additions for tax positions of current year		75	46
Settlements	(986)	(163)	(303)
Translation adjustments	18	(17)	(5)
Unrecognized tax benefits, Ending Balance	$ 806	$ 1,774	$ 1,910

Commitments - Future Contractua

Commitments - Future Contractual Obligations for Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,018	$ 12,506
2,019	11,442
2,020	10,835
2,021	9,409
2,022	8,001
Thereafter	29,490
Total minimum lease payments	$ 81,683

Commitments - Additional Inform

Commitments - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Aggregate rent expense	$ 17.4	$ 16.1	$ 16

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2012	Oct. 31, 2016	Jul. 31, 2015	Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized	500,000				500,000								500,000	500,000
Preferred stock, par value	$ 0.01				$ 0.01								$ 0.01	$ 0.01
Authorized to purchase of common stock under the stock repurchase program	$ 485,000,000												$ 485,000,000				$ 25,000,000	$ 25,000,000	$ 25,000,000
Cumulative repurchase of common stock	16,100,000												16,100,000
Aggregate cost of repurchase of common stock													$ 464,900,000
Dividend declared and paid per share	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.17	$ 0.17	$ 0.17	$ 0.17
Dividend declared per share													$ 0.76	$ 0.72	$ 0.68
Aggregate dividend declared for the year													$ 13,600,000	$ 13,000,000	$ 12,200,000
Option Outstanding and vested	937,000				1,540,000								937,000	1,540,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards granted or issued under plans	100,000												100,000
Shares authorized	700,000												700,000
Hours of work per week													20 hours
Duration of purchase periods under employee stock purchase plan													6 months
Holding period of stocks acquired under employee stock purchase plan													1 year
Value used to derive maximum number of shares per participant for employee stock purchase													$ 12,500
Employee maximum elected percentage reduction of compensation to purchase shares	10.00%												10.00%
Exercise price rate of fair value													85.00%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value for RSUs granted													$ 39.73	$ 37.87	$ 31.50
Number of shares received per restricted stock unit on lapse of restrictions and vesting condition met													1
Value of RSUs vested and converted to common stock													$ 8,700,000	$ 6,600,000	$ 4,600,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised													$ 4,500,000	$ 3,700,000	$ 400,000
1996 Equity Plan [Member] | Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards granted or issued under plans	0												0
2006 Director Plan [Member] | Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards granted or issued under plans	0												0
Shares authorized	450,000,000												450,000,000
Shares returned																80,000
Option Outstanding and vested	100,000												100,000
1996 Director [Member] | Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards granted or issued under plans	0												0
Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity incentive plan extended term													10 years
Equity incentive plan expiration													2026-05
Increase in number of shares issuable under plan													2,000,000
Equity Incentive Plan [Member] | Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Future awards granted or issued under plans	2,600,000												2,600,000
Shares authorized																6,350,000
Shares returned																713,275
Option expiration period													10 years
Equity Incentive Plan [Member] | Equity Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vested period													4 years
Equity Incentive Plan [Member] | Equity Plan [Member] | Non-Employee Directors [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vested period													1 year

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Restricted Stock Unit Activity (Detail) - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Unvested at December 31, 2016	539
Number of Shares, Granted	253
Number of Shares, Vested	(212)
Number of Shares, Forfeited	(71)
Number of Shares, Unvested at December 31, 2017	509	539
Weighted-Average Grant Date Fair Value, Unvested, Beginning Balance	$ 35.50
Weighted-Average Grant Date Fair Value, Granted	39.73	$ 37.87	$ 31.50
Weighted-Average Grant Date Fair Value, Vested	35.38
Weighted-Average Grant Date Fair Value, Forfeited	35.92
Weighted-Average Grant Date Fair Value, Unvested, Ending Balance	$ 37.59	$ 35.50

Stockholders' Equity - Schedu58

Stockholders' Equity - Schedule of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding at December 31, 2016	1,540,000
Number of Shares, Granted	0
Number of Shares, Exercised	(512,000)
Number of Shares, Forfeited	(91,000)
Number of Shares, Outstanding at December 31, 2017	937,000
Number of Shares, Exercisable at December 31, 2017	650,000
Number of Shares, Vested and expected to vest at December 31, 2017	937,000
Weighted - Average Exercise Price Per Share, Outstanding, Beginning balance | $ / shares	$ 34.35
Weighted - Average Exercise Price Per Share, Exercised | $ / shares	32.90
Weighted - Average Exercise Price Per Share, Forfeited | $ / shares	34.87
Weighted - Average Exercise Price Per Share, Outstanding, Ending balance | $ / shares	35.10
Weighted - Average Exercise Price Per Share, Exercisable at December 31, 2017 | $ / shares	34.98
Weighted - Average Exercise Price Per Share, Vested and expected to vest at December 31, 2017 | $ / shares	$ 35.10
Weighted - Average Remaining Contractual Term, Outstanding at December 31, 2017	5 years 10 months 9 days
Weighted - Average Remaining Contractual Term, Exercisable at December 31, 2017	5 years 1 month 28 days
Weighted - Average Remaining Contractual Term, Vested and expected to vest at December 31, 2017	5 years 10 months 9 days
Aggregate Intrinsic Value, Outstanding at December 31, 2017 | $	$ 8,529
Aggregate Intrinsic Value, Exercisable at December 31, 2017 | $	5,992
Aggregate Intrinsic Value, Vested and expected to vest at December 31, 2017 | $	$ 8,529

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shares Purchased by Employees Under the Stock Purchase Plan (Detail) - $ / shares shares in Thousands	6 Months Ended
	Aug. 31, 2017	Feb. 28, 2017	Aug. 31, 2016	Feb. 29, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Purchased	26	24	25	28
Purchase Price	$ 31.71	$ 31.03	$ 27.04	$ 26

Employee Pension Plans - Additi

Employee Pension Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Contribution to defined contribution plans	$ 5.2	$ 4.3	$ 4.1

Reorganization - Additional Inf

Reorganization - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015
Restructuring Cost And Reserve [Line Items]
Percentage of workforce reduction	2.00%		4.00%
Severance costs	$ 1		$ 3.2
Subsidiary Liquidation [Member]
Restructuring Cost And Reserve [Line Items]
Reorganization costs			$ 0.3
Products Group Reorganization [Member]
Restructuring Cost And Reserve [Line Items]
Severance costs		$ 0.7
Products Group Reorganization [Member] | Software Development Project [Member]
Restructuring Cost And Reserve [Line Items]
Expenses to write off		$ 0.2

Reorganization - Schedule of Ro

Reorganization - Schedule of Rolls Forward of Activity in Reorganization Accrual (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Restructuring Cost And Reserve [Line Items]
Accrual Beginning Balance	$ 481
Additions	1,026	$ 4,433
Cash payments	(1,507)
Accrual Ending Balance		481
Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Accrual Beginning Balance	41
Additions	1,022
Cash payments	(1,063)
Accrual Ending Balance		41
Subsidiary Liquidation [Member]
Restructuring Cost And Reserve [Line Items]
Accrual Beginning Balance	7
Cash payments	(7)
Accrual Ending Balance		7
Products Group Reorganization [Member]
Restructuring Cost And Reserve [Line Items]
Accrual Beginning Balance	433
Additions	4
Cash payments	$ (437)
Accrual Ending Balance		$ 433

Operating Segment and Enterpr63

Operating Segment and Enterprise Wide Reporting - Schedule of Information about Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Research services revenues									$ 216,471	$ 215,216	$ 210,268
Advisory services and events revenues									121,202	110,879	103,458
Total revenues	$ 90,377	$ 80,369	$ 89,733	$ 77,194	$ 83,446	$ 77,427	$ 87,821	$ 77,401	337,673	326,095	313,726
Segment expenses									119,494	112,165	110,184
Contribution margin (loss)									218,179	213,930	203,542
Selling, marketing, administrative and other expenses									(189,849)	(181,299)	(179,391)
Amortization of intangible assets									(781)	(831)	(891)
Reorganization costs										(1,026)	(4,433)
Other income and losses on investments									(178)	(65)	493
Income before income taxes									27,371	30,709	19,320
Product Segment [Member]
Segment Reporting Information [Line Items]
Research services revenues									216,471	215,216	210,268
Advisory services and events revenues									21,887	20,374	17,512
Total revenues									238,358	235,590	227,780
Segment expenses									45,205	41,528	38,615
Contribution margin (loss)									193,153	194,062	189,165
Research Segment [Member]
Segment Reporting Information [Line Items]
Advisory services and events revenues									45,054	44,631	42,422
Total revenues									45,054	44,631	42,422
Segment expenses									48,812	47,496	48,277
Contribution margin (loss)									(3,758)	(2,865)	(5,855)
Project Consulting [Member]
Segment Reporting Information [Line Items]
Advisory services and events revenues									54,261	45,874	43,524
Total revenues									54,261	45,874	43,524
Segment expenses									25,477	23,141	23,292
Contribution margin (loss)									$ 28,784	$ 22,733	$ 20,232

Operating Segment and Enterpr64

Operating Segment and Enterprise Wide Reporting - Schedule of Net Long-lived Tangible Assets by Location (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived tangible assets	$ 25,249	$ 23,894
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived tangible assets	23,943	22,150
United Kingdom [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived tangible assets	727	782
Europe (Excluding United Kingdom) [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived tangible assets	163	259
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Net long-lived tangible assets	$ 416	$ 703

Operating Segment and Enterpr65

Operating Segment and Enterprise Wide Reporting - Schedule of Revenues by Geographic Destination and as a Percentage of Total Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 90,377	$ 80,369	$ 89,733	$ 77,194	$ 83,446	$ 77,427	$ 87,821	$ 77,401	$ 337,673	$ 326,095	$ 313,726
Revenues by geographical area percentage									100.00%	100.00%	100.00%
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 260,077	$ 252,222	$ 241,025
Revenues by geographical area percentage									77.00%	77.00%	77.00%
Europe (Excluding United Kingdom) [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 28,525	$ 27,061	$ 24,607
Revenues by geographical area percentage									9.00%	8.00%	8.00%
United Kingdom [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 13,651	$ 14,808	$ 16,815
Revenues by geographical area percentage									4.00%	5.00%	5.00%
Canada [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 14,523	$ 13,806	$ 14,424
Revenues by geographical area percentage									4.00%	4.00%	5.00%
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ 20,897	$ 18,198	$ 16,855
Revenues by geographical area percentage									6.00%	6.00%	5.00%

Certain Balance Sheet Account66

Certain Balance Sheet Accounts - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Total property and equipment	$ 84,205	$ 77,498
Less accumulated depreciation	58,956	53,604
Total	25,249	23,894
Computers and Equipment [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	18,570	17,137
Computer Software [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	29,891	26,686
Furniture and Fixtures [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	9,094	8,471
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total property and equipment	$ 26,650	$ 25,204

Certain Balance Sheet Account67

Certain Balance Sheet Accounts - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Payroll and related benefits	$ 34,809	$ 28,681
Taxes	3,912	4,704
Other	10,908	8,018
Total	$ 49,629	$ 41,403

Certain Balance Sheet Account68

Certain Balance Sheet Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Balance, beginning of year	$ 140	$ 153	$ 188
Provision for doubtful accounts	331	150	106
Write-offs	(316)	(163)	(141)
Balance, end of year	$ 155	$ 140	$ 153

Summary Selected Quarterly Fi69

Summary Selected Quarterly Financial Data - Summary of Selected Consolidated Quarterly Financial Data (unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 90,377	$ 80,369	$ 89,733	$ 77,194	$ 83,446	$ 77,427	$ 87,821	$ 77,401	$ 337,673	$ 326,095	$ 313,726
Income from operations	7,451	6,749	10,213	3,136	9,038	7,552	11,472	2,712	27,549	30,774	18,827
Net income	$ 2,093	$ 3,953	$ 6,064	$ 3,030	$ 5,790	$ 3,112	$ 7,460	$ 1,289	$ 15,140	$ 17,651	$ 11,996
Basic income per common share	$ 0.12	$ 0.22	$ 0.34	$ 0.17	$ 0.32	$ 0.17	$ 0.42	$ 0.07	$ 0.84	$ 0.98	$ 0.67
Diluted income per common share	$ 0.11	$ 0.22	$ 0.34	$ 0.16	$ 0.31	$ 0.17	$ 0.41	$ 0.07	$ 0.83	$ 0.97	$ 0.66