Gartner (IT) 10-Q 3 Aug 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Jul. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	1-14443
Entity Registrant Name	Gartner, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3099750
Entity Address, Address Line One	P.O. Box 10212
Entity Address, Address Line Two	56 Top Gallant Road
Entity Address, City or Town	Stamford,
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06902-7700
City Area Code	203
Local Phone Number	316-1111
Title of 12(b) Security	Common Stock, $.0005 par value per share
Trading Symbol	IT
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		83,648,748
Entity Central Index Key	0000749251
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 796,257	$ 712,583
Fees receivable, net of allowances of $8,000 and $10,000, respectively	1,102,562	1,241,508
Deferred commissions	248,447	259,755
Prepaid expenses and other current assets	109,900	109,212
Total current assets	2,257,166	2,323,058
Property, equipment and leasehold improvements, net	309,222	336,765
Operating lease right-of-use assets	618,132	647,283
Goodwill	2,955,466	2,945,547
Intangible assets, net	775,479	806,998
Other assets	272,875	256,316
Total Assets	7,188,340	7,315,967
Current liabilities:
Accounts payable and accrued liabilities	752,241	952,431
Deferred revenues	2,152,043	1,974,548
Current portion of long-term debt	5,322	20,515
Total current liabilities	2,909,606	2,947,494
Long-term debt, net of deferred financing fees	2,457,854	1,958,286
Operating lease liabilities	745,108	780,166
Other liabilities	548,134	539,593
Total Liabilities	6,660,702	6,225,539
Stockholders’ Equity
Preferred stock, $0.01 par value, 5,000,000 shares authorized; none issued or outstanding	0	0
Common stock, $0.0005 par value, 250,000,000 shares authorized; 163,602,067 shares issued for both periods	82	82
Additional paid-in capital	2,031,726	1,968,930
Accumulated other comprehensive loss, net	(82,978)	(99,228)
Accumulated earnings	2,690,803	2,255,467
Treasury stock, at cost, 79,464,479 and 74,759,985 common shares, respectively	(4,111,995)	(3,034,823)
Total Stockholders’ Equity	527,638	1,090,428
Total Liabilities and Stockholders’ Equity	$ 7,188,340	$ 7,315,967

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Fees receivable, allowance	$ 8,000	$ 10,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0005	$ 0.0005
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	163,602,067	163,602,067
Treasury stock shares (in shares)	79,464,479	74,759,985

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Total revenues	$ 1,167,319	$ 973,135	$ 2,271,357	$ 1,992,026
Costs and expenses:
Cost of services and product development	350,802	322,551	685,269	663,829
Selling, general and administrative	488,496	494,840	975,751	991,479
Depreciation	25,851	22,728	51,601	45,245
Amortization of intangibles	26,154	31,208	56,668	63,387
Acquisition and integration charges	1,302	2,157	1,942	3,716
Total costs and expenses	892,605	873,484	1,771,231	1,767,656
Operating income	274,714	99,651	500,126	224,370
Interest expense, net	(27,390)	(30,296)	(53,539)	(56,644)
Gain on event cancellation insurance claims	135,545	0	135,545	0
Other (expense) income, net	(3,682)	(10,399)	11,808	(11,915)
Income before income taxes	379,187	58,956	593,940	155,811
Provision for income taxes	107,951	3,879	158,604	25,637
Net income	$ 271,236	$ 55,077	$ 435,336	$ 130,174
Net income per share:
Basic (in dollars per share)	$ 3.16	$ 0.62	$ 5	$ 1.46
Diluted (in dollars per share)	$ 3.13	$ 0.61	$ 4.95	$ 1.45
Weighted average shares outstanding:
Basic (in shares)	85,712	89,323	87,032	89,271
Diluted (in shares)	86,589	89,780	87,921	89,967
Research
Revenues:
Total revenues	$ 1,003,238	$ 875,329	$ 1,982,970	$ 1,784,620
Conferences
Revenues:
Total revenues	58,179	317	82,981	14,187
Consulting
Revenues:
Total revenues	$ 105,902	$ 97,489	$ 205,406	$ 193,219

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 271,236	$ 55,077	$ 435,336	$ 130,174
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	4,639	23,817	5,316	(22,564)
Interest rate swaps – net change in deferred gain or loss	5,457	2,900	10,727	(41,832)
Pension plans – net change in deferred actuarial loss	104	80	207	159
Other comprehensive income (loss), net of tax	10,200	26,797	16,250	(64,237)
Comprehensive income	$ 281,436	$ 81,874	$ 451,586	$ 65,937

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss, Net	Accumulated Earnings	Treasury Stock
Beginning balance at Dec. 31, 2019	$ 938,593	$ 82	$ 1,899,273	$ (77,938)	$ 1,988,722	$ (2,871,546)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	75,097				75,097
Other comprehensive income (loss)	(91,034)			(91,034)
Issuances under stock plans	5,654		(1,794)			7,448
Common share repurchases	(63,164)					(63,164)
Stock-based compensation expense	25,129		25,129
Ending balance at Mar. 31, 2020	890,275	82	1,922,608	(168,972)	2,063,819	(2,927,262)
Beginning balance at Dec. 31, 2019	938,593	82	1,899,273	(77,938)	1,988,722	(2,871,546)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	130,174
Other comprehensive income (loss)	(64,237)
Ending balance at Jun. 30, 2020	991,219	82	1,941,509	(142,175)	2,118,896	(2,927,093)
Beginning balance at Mar. 31, 2020	890,275	82	1,922,608	(168,972)	2,063,819	(2,927,262)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	55,077				55,077
Other comprehensive income (loss)	26,797			26,797
Issuances under stock plans	4,090		3,223			867
Common share repurchases	(698)					(698)
Stock-based compensation expense	15,678		15,678
Ending balance at Jun. 30, 2020	991,219	82	1,941,509	(142,175)	2,118,896	(2,927,093)
Beginning balance at Dec. 31, 2020	1,090,428	82	1,968,930	(99,228)	2,255,467	(3,034,823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	164,100				164,100
Other comprehensive income (loss)	6,050			6,050
Issuances under stock plans	5,380		(1,543)			6,923
Common share repurchases	(410,450)					(410,450)
Stock-based compensation expense	36,086		36,086
Ending balance at Mar. 31, 2021	891,594	82	2,003,473	(93,178)	2,419,567	(3,438,350)
Beginning balance at Dec. 31, 2020	1,090,428	82	1,968,930	(99,228)	2,255,467	(3,034,823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	435,336
Other comprehensive income (loss)	16,250
Ending balance at Jun. 30, 2021	527,638	82	2,031,726	(82,978)	2,690,803	(4,111,995)
Beginning balance at Mar. 31, 2021	891,594	82	2,003,473	(93,178)	2,419,567	(3,438,350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	271,236				271,236
Other comprehensive income (loss)	10,200			10,200
Issuances under stock plans	4,080		2,063			2,017
Common share repurchases	(675,662)					(675,662)
Stock-based compensation expense	26,190		26,190
Ending balance at Jun. 30, 2021	$ 527,638	$ 82	$ 2,031,726	$ (82,978)	$ 2,690,803	$ (4,111,995)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities:
Net income	$ 435,336	$ 130,174
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	108,269	108,632
Stock-based compensation expense	62,276	40,807
Deferred taxes	2,294	(1,813)
Reduction in the carrying amount of operating lease right-of-use assets	37,261	43,256
Amortization and write-off of deferred financing fees	1,914	5,392
Amortization of deferred swap losses from de-designation	0	10,320
Gain on de-designated swaps	(11,751)	0
Changes in assets and liabilities:
Fees receivable, net	132,650	261,124
Deferred commissions	10,494	31,255
Prepaid expenses and other current assets	(822)	14,202
Other assets	(23,769)	(932)
Deferred revenues	190,814	(149,615)
Accounts payable and accrued and other liabilities	(212,321)	(93,885)
Cash provided by operating activities	732,645	398,917
Investing activities:
Additions to property, equipment and leasehold improvements	(24,479)	(45,865)
Acquisitions - cash paid (net of cash acquired)	(22,774)	0
Cash used in investing activities	(47,253)	(45,865)
Financing activities:
Proceeds from employee stock purchase plan	9,414	9,719
Proceeds from borrowings	600,000	800,000
Payments of deferred financing fees	(6,045)	(10,516)
Proceeds from revolving credit facility	0	327,000
Payments on revolving credit facility	(5,000)	(475,000)
Payments on borrowings	(105,256)	(853,094)
Purchases of treasury stock	(1,083,350)	(73,862)
Cash used in financing activities	(590,237)	(275,753)
Net increase in cash and cash equivalents and restricted cash	95,155	77,299
Effects of exchange rates on cash and cash equivalents	(7,281)	(1,502)
Cash and cash equivalents, beginning of period	712,583	280,836
Cash and cash equivalents and restricted cash, end of period	$ 800,457	$ 356,633

Business and Basis of Presentat

Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Business. Gartner, Inc. (NYSE: IT) is the world’s leading research and advisory company and a member of the S&P 500. We equip business leaders with indispensable insights, advice and tools to achieve their mission–critical priorities today and build the successful organizations of tomorrow. We believe our unmatched combination of expert-led, practitioner-sourced and data-driven research steers clients toward the right decisions on the issues that matter most. We are a trusted advisor and an objective resource for more than 14,000 enterprises in more than 100 countries — across all major functions, in every industry and enterprise size. Segments . Gartner delivers its products and services globally through three business segments: Research, Conferences and Consulting. Revenues and other financial information for our segments are discussed in Note 7 — Segment Information. Basis of presentation . The accompanying interim Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”), as defined in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 270 for interim financial information and with the applicable instructions of U.S. Securities and Exchange Commission (“SEC”) Rule 10-01 of Regulation S-X on Form 10-Q, and should be read in conjunction with the consolidated financial statements and related notes of the Company in its Annual Report on Form 10-K for the year ended December 31, 2020. The fiscal year of Gartner is the twelve-month period from January 1 through December 31. In the opinion of management, all normal recurring accruals and adjustments considered necessary for a fair presentation of financial position, results of operations and cash flows at the dates and for the periods presented herein have been included. The results of operations for the three and six months ended June 30, 2021 may not be indicative of the results of operations for the remainder of 2021 or beyond. When used in these notes, the terms “Gartner,” the “Company,” “we,” “us,” or “our” refer to Gartner, Inc. and its consolidated subsidiaries. Principles of consolidation . The accompanying interim Condensed Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated. Use of estimates . The preparation of the accompanying interim Condensed Consolidated Financial Statements requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of fees receivable, goodwill, intangible assets and other long-lived assets, as well as tax accruals and other liabilities. In addition, estimates are used in revenue recognition, income tax expense or benefit, performance-based compensation charges, depreciation and amortization. Management believes its use of estimates in these interim Condensed Consolidated Financial Statements to be reasonable. Management continually evaluates and revises its estimates using historical experience and other factors, including the general economic environment and actions it may take in the future. Management adjusts these estimates when facts and circumstances dictate. However, these estimates may involve significant uncertainties and judgments and cannot be determined with precision. In addition, these estimates are based on management’s best judgment at a point in time. As a result, differences between estimates and actual results could be material and would be reflected in the Company’s consolidated financial statements in future periods. Cash and cash equivalents and restricted cash. For the six months ended June 30, 2021, the end of period cash and cash equivalents and restricted cash balance of $800.5 million in the accompanying Condensed Consolidated Statements of Cash Flows consisted of $796.3 million of cash and cash equivalents and $4.2 million of restricted cash. The restricted cash was classified in Other Assets in the accompanying Condensed Consolidated Balance Sheets as of June 30, 2021. Revenue recognition. Revenue is recognized in accordance with the requirements of FASB ASC Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). Revenue is only recognized when all of the required criteria for revenue recognition have been met. The accompanying Condensed Consolidated Statements of Operations present revenue net of any sales or value-added taxes that we collect from customers and remit to government authorities. ASC Topic 270 requires certain disclosures in interim financial statements around the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Note 4 — Revenue and Related Matters provides additional information regarding the Company’s revenues. Gain on event cancellation insurance claims. In May 2021, the Company received $150.0 million of proceeds related to 2020 event cancellation insurance claims, and recorded a pre-tax gain of $135.5 million. The Company does not record any gain on insurance claims in excess of expenses incurred until the receipt of the insurance proceeds is deemed to be realizable. Adoption of new accounting standards. The Company adopted the accounting standard described below during the six months ended June 30, 2021. Simplifying the Accounting for Income Taxes — In December 2019, the FASB issued ASU No. 2019-12, Income Taxes—Simplifying the Accounting for Income Taxes (“ASU No. 2019-12”). ASU No. 2019-12 provides new guidance to simplify the accounting for income taxes in certain areas, changes the accounting for select income tax transactions and makes minor ASC improvements. Gartner adopted ASU No. 2019-12 on January 1, 2021. The adoption of ASU No. 2019-12 did not have a material impact on the Company’s Condensed Consolidated Financial Statements. Accounting standards issued but not yet adopted. The FASB has issued accounting standards that have not yet become effective and may impact the Company’s consolidated financial statements or related disclosures in future periods. Those standards and their potential impact are discussed below. Accounting standard effective immediately upon voluntary election by Gartner Reference Rate Reform — In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform—Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU No. 2020-04”). ASU No. 2020-04 provides that an entity can elect not to apply certain required modification accounting in U.S. GAAP to contracts where all changes to the critical terms relate to reference rate reform (e.g., the expected discontinuance of LIBOR and the transition to an alternative reference interest rate, etc.). In addition, the rule provides optional expedients and exceptions that enable entities to continue to apply hedge accounting for hedging relationships where one or more of the critical terms change due to reference rate reform. The rule became effective for all entities as of March 12, 2020 and will generally no longer be available to apply after December 31, 2022. The Company is currently evaluating the potential impact of ASU No. 2020-04 on its consolidated financial statements, including the rule’s potential impact on any debt modifications or other contractual changes in the future that may result from reference rate reform.

Acquisition

Acquisition	6 Months Ended
	Jun. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisition	Acquisition On June 17, 2021, the Company acquired 100% of the outstanding capital stock of Pulse Q&A Inc. (“Pulse”), a privately-held company based in San Francisco, California, for an aggregate purchase price of $30.0 million. Pulse is a technology-enabled community platform. For cash flow reporting purposes, the Company paid $22.8 million in cash for Pulse after considering the cash acquired with the business, amounts held in escrow and certain other purchase price adjustments at closing. In addition to the purchase price, the Company may also be required to pay up to $4.5 million in cash in the future based on the continuing employment of certain key employees. Such amount will be recognized as compensation expense over three years and reported in Acquisition and integration charges in the Consolidated Statements of Operations. The Company recorded $30.6 million of goodwill and finite-lived intangible assets for Pulse and $0.6 million of other liabilities on a net basis. The Company believes that the recorded goodwill is supported by the anticipated synergies resulting from the acquisition. None of the recorded goodwill will be deductible for tax purposes. The fair value measurements of the intangible assets were based primarily on an incremental profits valuation methodology, which includes significant unobservable inputs and thus represent a Level 3 measurement as defined in FASB ASC Topic 820. The allocation of the purchase price is preliminary with respect to certain tax matters and the finalization of working capital adjustments and the valuation of finite-lived intangible assets. The operating results of the acquired Pulse business and the related goodwill are being reported as part of the Company’s Research segment. T he operating results of Pulse have been included in the Company’s consolidated financial statements since the date of acquisition; however, such operating results were not material to the Company’s consolidated operating results and segment results. Had the Company acquired Pulse in prior periods, the impact on the Company’s operating results would not have been material and, as a result, pro forma financial information for prior periods has not been presented herein.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill Goodwill represents the excess of the purchase price of acquired businesses over the estimated fair values of the tangible and identifiable intangible net assets acquired. Evaluations of the recoverability of goodwill are performed in accordance with FASB ASC Topic 350, which requires an annual assessment of potential goodwill impairment at the reporting unit level and whenever events or changes in circumstances indicate that the carrying value of goodwill may not be recoverable. When performing the annual assessment of the recoverability of goodwill, the Company initially performs a qualitative analysis evaluating whether any events or circumstances occurred or exist that provide evidence that it is more likely than not that the fair value of any of the Company’s reporting units is less than the related carrying amount. If the Company does not believe that it is more likely than not that the fair value of any of the Company’s reporting units is less than the related carrying amount, then no quantitative impairment test is performed. However, if the results of the qualitative assessment indicate that it is more likely than not that the fair value of a reporting unit is less than its respective carrying amount, then a quantitative impairment test is performed. Evaluating the recoverability of goodwill requires judgments and assumptions regarding future trends and events. As a result, both the precision and reliability of the estimates are subject to uncertainty. The Company’s most recent annual impairment test of goodwill was a qualitative analysis conducted during the quarter ended September 30, 2020 that indicated no impairment. Subsequent to completing the 2020 annual impairment test, there were no events or changes in circumstances noted that required an interim impairment test. The table below presents changes to the carrying amount of goodwill by segment during the six months ended June 30, 2021 (in thousands). Research Conferences Consulting Total Balance at December 31, 2020 (1) $ 2,664,732 $ 184,091 $ 96,724 $ 2,945,547 Additions due to an acquisition (2) 11,172 — — 11,172 Foreign currency translation impact (1,398) (20) 165 (1,253) Balance at June 30, 2021 (1) $ 2,674,506 $ 184,071 $ 96,889 $ 2,955,466 (1) The Company does not have any accumulated goodwill impairment losses. (2) The additions were due to the acquisition of Pulse on June 17, 2021. See Note 2 — Acquisition for additional information. Finite-Lived Intangible Assets The tables below present reconciliations of the carrying amounts of the Company’s finite-lived intangible assets as of the dates indicated (in thousands). June 30, 2021 Customer Software Content Other Total Gross cost at December 31, 2020 $ 1,154,210 $ 110,597 $ 3,965 $ 10,614 $ 1,279,386 Additions due to an acquisition (1) 7,980 11,200 — 280 19,460 Intangible assets fully amortized (17,788) (60,631) (3,965) — (82,384) Foreign currency translation impact 7,895 226 — — 8,121 Gross cost 1,152,297 61,392 — 10,894 1,224,583 Accumulated amortization (2) (414,460) (30,394) — (4,250) (449,104) Balance at June 30, 2021 $ 737,837 $ 30,998 $ — $ 6,644 $ 775,479 December 31, 2020 Customer Software Content Other Total Gross cost $ 1,154,210 $ 110,597 $ 3,965 $ 10,614 $ 1,279,386 Accumulated amortization (2) (381,776) (83,320) (3,595) (3,697) (472,388) Balance at December 31, 2020 $ 772,434 $ 27,277 $ 370 $ 6,917 $ 806,998 (1) The additions were due to the acquisition of Pulse on June 17, 2021. See Note 2 — Acquisition for additional information. (2) Finite-lived intangible assets are amortized using the straight-line method over the following periods: Customer relationships—6 to 13 years; Software—3 to 7 years; Content—2 to 3 years; and Other—2 to 11 years. Amortization expense related to finite-lived intangible assets was $26.2 million and $31.2 million during the three months ended June 30, 2021 and 2020, respectively, and $56.7 million and $63.4 million during the six months ended June 30, 2021 and 2020. The estimated future amortization expense by year for finite-lived intangible assets is presented in the table below (in thousands). 2021 (remaining six months) $ 52,600 2022 101,768 2023 101,752 2024 94,540 2025 84,001 Thereafter 340,818 $ 775,479

Revenue and Related Matters

Revenue and Related Matters	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue and Related Matters	Revenue and Related Matters Disaggregated Revenue — The Company’s disaggregated revenue by reportable segment is presented in the tables below for the periods indicated (in thousands). By Primary Geographic Market (1) Three Months Ended June 30, 2021 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 646,432 $ 40,328 $ 59,605 $ 746,365 Europe, Middle East and Africa 236,756 14,468 35,459 286,683 Other International 120,050 3,383 10,838 134,271 Total revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Three Months Ended June 30, 2020 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 573,245 $ 317 $ 58,017 $ 631,579 Europe, Middle East and Africa 196,854 — 30,114 226,968 Other International 105,230 — 9,358 114,588 Total revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Six Months Ended June 30, 2021 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 1,277,765 $ 59,927 $ 117,091 $ 1,454,783 Europe, Middle East and Africa 466,957 17,181 65,821 $ 549,959 Other International 238,248 5,873 22,494 $ 266,615 Total revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Six Months Ended June 30, 2020 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 1,163,400 $ 6,297 $ 112,181 $ 1,281,878 Europe, Middle East and Africa 402,794 2,147 60,196 465,137 Other International 218,426 5,743 20,842 245,011 Total revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 (1) Revenue is reported based on where the sale is fulfilled. The Company’s revenue is generated primarily through direct sales to clients by domestic and international sales forces and a network of independent international sales agents. Most of the Company’s products and services are provided on an integrated worldwide basis and, because of this integrated delivery approach, it is not practical to precisely separate the Company’s revenue by geographic location. Accordingly, revenue information presented in the above tables is based on internal allocations, which involve certain management estimates and judgments. By Timing of Revenue Recognition Three Months Ended June 30, 2021 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 916,754 $ — $ 85,989 $ 1,002,743 Transferred at a point in time (2) 86,484 58,179 19,913 164,576 Total revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Three Months Ended June 30, 2020 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 810,564 $ — $ 68,630 $ 879,194 Transferred at a point in time (2) 64,765 317 28,859 93,941 Total revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Six Months Ended June 30, 2021 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 1,810,841 $ — $ 170,331 $ 1,981,172 Transferred at a point in time (2) 172,129 82,981 35,075 290,185 Total revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Six Months Ended June 30, 2020 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 1,639,776 $ — $ 150,038 $ 1,789,814 Transferred at a point in time (2) 144,844 14,187 43,181 202,212 Total revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 (1) Research revenues were recognized in connection with performance obligations that were satisfied over time using a time-elapsed output method to measure progress. Consulting revenues were recognized over time using labor hours as an input measurement basis. (2) The revenues in this category were recognized in connection with performance obligations that were satisfied at the point in time that the contractual deliverables were provided to the customer. Performance Obligations — For customer contracts that are greater than one year in duration, the aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially unsatisfied) as of June 30, 2021 was approximately $3.7 billion. The Company expects to recognize $1,229.3 million, $1,754.2 million and $676.9 million of this revenue (most of which pertains to Research) during the remainder of 2021, the year ending December 31, 2022 and thereafter, respectively. The Company applies a practical expedient that is permitted under ASC Topic 606 and, accordingly, it does not disclose such performance obligation information for customer contracts that have original durations of one year or less. The Company’s performance obligations for contracts meeting this ASC Topic 606 disclosure exclusion primarily include: (i) stand-ready services under Research subscription contracts; (ii) holding conferences and meetings where attendees and exhibitors can participate; and (iii) providing customized Consulting solutions for clients under fixed fee and time and materials engagements. The remaining duration of these performance obligations is generally less than one year, which aligns with the period that the parties have enforceable rights and obligations under the affected contracts. Customer Contract Assets and Liabilities — The timing of the recognition of revenue and the amount and timing of the Company’s billings and cash collections, including upfront customer payments, result in the recognition of both assets and liabilities on the Company’s consolidated balance sheet. The table below provides information regarding certain of the Company’s balance sheet accounts that pertain to its contracts with customers (in thousands). June 30, December 31, 2021 2020 Assets: Fees receivable, gross (1) $ 1,110,562 $ 1,251,508 Contract assets recorded in Prepaid expenses and other current assets (2) $ 22,637 $ 14,440 Contract liabilities: Deferred revenues (current liability) (3) $ 2,152,043 $ 1,974,548 Non-current deferred revenues recorded in Other liabilities (3) 31,826 26,754 Total contract liabilities $ 2,183,869 $ 2,001,302 (1) Fees receivable represent an unconditional right to payment from the Company’s customers and include both billed and unbilled amounts. (2) Contract assets represent recognized revenue for which the Company does not have an unconditional right to payment as of the balance sheet date because the project may be subject to a progress billing milestone or some other billing restriction. (3) Deferred revenues represent amounts (i) for which the Company has received an upfront customer payment or (ii) that pertain to recognized fees receivable. Both situations occur before the completion of the Company’s performance obligation(s). The Company recognized revenue of $817.3 million and $692.6 million during the three months ended June 30, 2021 and 2020, respectively, and $1,261.9 million and $1,087.9 million during the six months ended June 30, 2021 and 2020, respectively, that was attributable to deferred revenues that were recorded at the beginning of each such period. Those amounts primarily consisted of (i) Research revenues that were recognized ratably as control of the goods or services passed to the customer and (ii) Conferences revenue pertaining to conferences and meetings that occurred during the reporting periods. During each of the three and six months ended June 30, 2021 and 2020, the Company did not record any material impairments related to its contract assets. The Company does not typically recognize revenue from performance obligations satisfied in prior periods.

Computation of Earnings Per Sha

Computation of Earnings Per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Computation of Earnings Per Share	Computation of Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average number of shares of Common Stock outstanding during the period. Diluted EPS reflects the potential dilution of securities that could share in earnings. Potential shares of common stock are excluded from the computation of diluted earnings per share when their effect would be anti-dilutive. The table below sets forth the calculation of basic and diluted income per share for the periods indicated (in thousands, except per share data). Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Numerator: Net income used for calculating basic and diluted income per share $ 271,236 $ 55,077 $ 435,336 $ 130,174 Denominator: Weighted average common shares used in the calculation of basic income per share 85,712 89,323 87,032 89,271 Dilutive effect of outstanding awards associated with stock-based compensation plans (1) 877 457 889 696 Shares used in the calculation of diluted income per share 86,589 89,780 87,921 89,967 Basic income per share $ 3.16 $ 0.62 $ 5.00 $ 1.46 Diluted income per share $ 3.13 $ 0.61 $ 4.95 $ 1.45 (1) Certain potential shares of common stock were not included in the computation of diluted income per share because the effect would have been anti-dilutive. For the three and six months ended June 30, 2021, approximately 0.1 million shares of common stock equivalents were excluded for both periods from the calculation of diluted income per share because they were anti-dilutive. For the three and six months ended June 30, 2020, approximately 1.3 million and 0.8 million shares of common stock equivalents, respectively, were excluded because of their anti-dilutive effect.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company grants stock-based compensation awards as an incentive for employees and directors to contribute to the Company’s long-term success. The Company currently awards stock-settled stock appreciation rights, service-based and performance-based restricted stock units, and common stock equivalents. As of June 30, 2021, the Company had 4.2 million shares of its common stock, par value $0.0005 per share, (the “Common Stock”) available for stock-based compensation awards under its current Long-Term Incentive Plan as amended and restated in January 2019 (the “Plan”). The tables below summarize the Company’s stock-based compensation expense by award type and expense category line item during the periods indicated (in millions). Three Months Ended Six Months Ended June 30, June 30, Award type 2021 2020 2021 2020 Stock appreciation rights $ 2.0 $ 1.9 $ 4.0 $ 3.6 Restricted stock units (2) 24.0 13.6 57.9 36.8 Common stock equivalents 0.2 0.2 0.4 0.4 Total (1) $ 26.2 $ 15.7 $ 62.3 $ 40.8 Three Months Ended Six Months Ended June 30, June 30, Expense category line item 2021 2020 2021 2020 Cost of services and product development $ 8.0 $ 7.1 $ 21.7 $ 19.2 Selling, general and administrative 18.2 8.6 40.6 21.6 Total (1) (2) $ 26.2 $ 15.7 $ 62.3 $ 40.8 (1) Includes charges of $11.3 million and $5.2 million during the three months ended June 30, 2021 and 2020, respectively, and $32.8 million and $16.8 million during the six months ended June 30, 2021 and 2020, respectively, for awards to retirement-eligible employees. Those awards vest on an accelerated basis. (2) On February 5, 2020, prior to the COVID-19 related shutdown in the U.S., the Compensation Committee (“Committee”) of the Board of Directors of the Company established performance measures for the performance-based restricted stock units (the “PSUs”) awarded to the Company’s executive officers in 2020 under the Plan. Based on preliminary corporate performance results for the 2020 performance measures, the 2020 PSUs would have been earned at 50% of target. However,

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Segment Information	Segment Information The Company’s products and services are delivered through three segments – Research, Conferences and Consulting, as described below. • Research provides trusted, objective insights and advice on the mission-critical priorities of leaders across all functional areas of an enterprise through reports, briefings, proprietary tools, access to our research experts, peer networking services and membership programs that enable our clients to drive organizational performance. • Conferences provides business professionals across an organization the opportunity to learn, share and network. From our Gartner Symposium/Xpo series, to industry-leading conferences focused on specific business roles and topics, to peer-driven sessions, our offerings enable attendees to experience the best of Gartner insight and advice. • Consulting combines the power of Gartner market-leading research with custom analysis and on-the-ground support to help chief information officers and other senior executives driving technology-related strategic initiatives move confidently from insight to action. The Company evaluates segment performance and allocates resources based on gross contribution margin. Gross contribution, as presented in the tables below, is defined as operating income or loss excluding certain Cost of services and product development expenses, Selling, general and administrative expenses, Depreciation, Amortization of intangibles, and Acquisition and integration charges. Certain bonus and fringe benefit costs included in consolidated Cost of services and product development are not allocated to segment expense. The accounting policies used by the reportable segments are the same as those used by the Company. There are no intersegment revenues. The Company does not identify or allocate assets, including capital expenditures, by reportable segment. Accordingly, assets are not reported by segment because the information is not available by segment and is not reviewed in the evaluation of segment performance or in making decisions regarding the allocation of resources. The tables below present information about the Company’s reportable segments for the periods indicated (in thousands). Three Months Ended June 30, 2021 Research Conferences Consulting Consolidated Revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Gross contribution 742,131 42,602 42,770 827,503 Corporate and other expenses (552,789) Operating income $ 274,714 Three Months Ended June 30, 2020 Research Conferences Consulting Consolidated Revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Gross contribution 632,624 (11,230) 33,542 654,936 Corporate and other expenses (555,285) Operating income $ 99,651 Six Months Ended June 30, 2021 Research Conferences Consulting Consolidated Revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Gross contribution 1,466,503 56,498 81,868 1,604,869 Corporate and other expenses (1,104,743) Operating income $ 500,126 Six Months Ended June 30, 2020 Research Conferences Consulting Consolidated Revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 Gross contribution 1,286,094 (17,290) 62,925 1,331,729 Corporate and other expenses (1,107,359) Operating income $ 224,370 The table below provides a reconciliation of total segment gross contribution to net income for the periods indicated (in thousands). Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Total segment gross contribution $ 827,503 $ 654,936 $ 1,604,869 $ 1,331,729 Costs and expenses: Cost of services and product development - unallocated (1) 10,986 4,352 18,781 3,532 Selling, general and administrative 488,496 494,840 975,751 991,479 Depreciation and amortization 52,005 53,936 108,269 108,632 Acquisition and integration charges 1,302 2,157 1,942 3,716 Operating income 274,714 99,651 500,126 224,370 Interest expense and other, net (31,072) (40,695) (41,731) (68,559) Gain on event cancellation insurance claims 135,545 — 135,545 — Less: Provision for income taxes 107,951 3,879 158,604 25,637 Net income $ 271,236 $ 55,077 $ 435,336 $ 130,174 (1) The unallocated amounts consist of certain bonus and fringe costs recorded in consolidated Cost of services and product development that are not allocated to segment expense. The Company’s policy is to allocate bonuses to segments at 100% of a segment employee’s target bonus. Amounts above or below 100% are absorbed by corporate.

Debt

Debt	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt The Company’s total outstanding borrowings are summarized in the table below (in thousands). June 30, December 31, Description 2021 2020 2020 Credit Agreement - Term loan facility (1) $ 290,000 $ 395,000 2020 Credit Agreement - Revolving credit facility (1), (2) — 5,000 Senior Notes due 2028 (“2028 Notes”) (3) 800,000 800,000 Senior Notes due 2029 (“2029 Notes”) (4) 600,000 — Senior Notes due 2030 (“2030 Notes”) (5) 800,000 800,000 Other (6) 5,790 6,046 Principal amount outstanding (7) 2,495,790 2,006,046 Less: deferred financing fees (8) (32,614) (27,245) Net balance sheet carrying amount $ 2,463,176 $ 1,978,801 (1) The contractual annualized interest rate as of June 30, 2021 on the 2020 Credit Agreement Term loan facility and the revolving credit facility was 1.50%, which consisted of a floating Eurodollar base rate of 0.125% plus a margin of 1.375%. However, the Company has interest rate swap contracts that effectively convert the floating Eurodollar base rates on outstanding amounts to a fixed base rate. (2) The Company had approximately $1.0 billion of available borrowing capacity on the 2020 Credit Agreement revolver (not including the expansion feature) as of June 30, 2021. (3) Consists of $800.0 million principal amount of 2028 Notes outstanding. The 2028 Notes bear interest at a fixed rate of 4.50% and mature on July 1, 2028. (4) Consists of $600.0 million principal amount of 2029 Notes outstanding. The 2029 Notes bear interest at a fixed rate of 3.625% and mature on June 15, 2029. (5) Consists of $800.0 million principal amount of 2030 Notes outstanding. The 2030 Notes bear interest at a fixed rate of 3.75% and mature on October 1, 2030. (6) Consists of two State of Connecticut economic development loans. One of the loans originated in 2012, has a 10-year maturity and the outstanding balance of $0.8 million as of June 30, 2021 bears interest at a fixed rate of 3.00%. The second loan, originated in 2019, has a 10-year maturity and bears interest at a fixed rate of 1.75%. Both of these loans may be repaid at any time by the Company without penalty. (7) The weighted average annual effective rate on the Company’s outstanding debt for the three and six months ended June 30, 2021, including the effects of its interest rate swaps discussed below, was 4.96% and 4.99%, respectively. (8) Deferred financing fees are being amortized to Interest expense, net over the term of the related debt obligation. 2029 Notes On June 18, 2021, the Company issued $600.0 million aggregate principal amount of 3.625% Senior Notes due 2029. The 2029 Notes were issued pursuant to an indenture, dated as of June 18, 2021 (the “2029 Note Indenture”), among the Company, the guarantors party thereto and U.S. Bank National Association, as trustee (the “Trustee”). The 2029 Notes were issued at an issue price of 100.0% and bear interest at a rate of 3.625% per annum. Interest on the 2029 Notes is payable on June 15 and December 15 of each year, beginning on December 15, 2021. The 2029 Notes will mature on June 15, 2029. The Company used a portion of the net proceeds of the 2029 Notes (i) to repay $100.0 million of the outstanding borrowings under the Company’s existing term loan facility and (ii) to pay related fees and expenses. The Company intends to use the remaining net proceeds of the 2029 Notes for general corporate purposes. The Company may redeem some or all of the 2029 Notes at any time on or after June 15, 2024 for cash at the redemption prices set forth in the 2029 Notes Indenture, plus accrued and unpaid interest to, but excluding, the redemption date. Prior to June 15, 2024, the Company may redeem up to 40% of the aggregate principal amount of the 2029 Notes with the proceeds of certain equity offerings at a redemption price of 103.625% plus accrued and unpaid interest to, but excluding, the redemption date. In addition, the Company may redeem some or all of the 2029 Notes prior to June 15, 2024, at a redemption price of 100% of the principal amount of the 2029 Notes plus accrued and unpaid interest to, but excluding, the redemption date, plus a “make-whole” premium. If the Company experiences specific kinds of change of control and a ratings decline, it will be required to offer to repurchase the 2029 Notes at a price equal to 101% of the principal amount thereof plus accrued and unpaid interest to, but excluding, the repurchase date. The 2029 Notes are the Company’s general unsecured senior obligations, and are effectively subordinated to all of the Company’s existing and future secured indebtedness to the extent of the value of the collateral securing such indebtedness, structurally subordinated to all existing and future indebtedness and other liabilities of the Company’s non-guarantor subsidiaries, equal in right of payment to all of the Company’s and Company’s guarantor subsidiaries’ existing and future senior indebtedness and senior in right of payment to all of the Company’s future subordinated indebtedness, if any. The 2029 Notes are jointly and severally guaranteed on a senior unsecured basis by certain of the Company’s domestic subsidiaries that have outstanding indebtedness or guarantee other specified indebtedness. The 2029 Notes Indenture contains covenants that limit, among other things, the Company’s ability and the ability of some of the Company’s subsidiaries to: • create liens; and • merge or consolidate with other entities. These covenants will be subject to a number of exceptions and qualifications. The 2029 Notes Indenture also provides for events of default, which, if any of them occurs, would permit or require the principal, premium, if any, and interest on all the then outstanding 2029 Notes issued under the Indenture to be due and payable. 2030 Notes On September 28, 2020, the Company issued $800.0 million aggregate principal amount of 3.75% Senior Notes due 2030. The 2030 Notes were issued pursuant to an indenture, dated as of September 28, 2020 (the “2030 Note Indenture”), among the Company, the guarantors party thereto and U.S. Bank National Association, as trustee. The 2030 Notes were issued at an issue price of 100.0% and bear interest at a rate of 3.75% per annum. Interest on the 2030 Notes is payable on April 1 and October 1 of each year, beginning on April 1, 2021. The 2030 Notes will mature on October 1, 2030. The Company may redeem some or all of the 2030 Notes at any time on or after October 1, 2025 for cash at the redemption prices set forth in the 2030 Note Indenture, plus accrued and unpaid interest to, but excluding, the redemption date. Prior to October 1, 2025, the Company may redeem up to 40% of the aggregate principal amount of the 2030 Notes in connection with certain equity offerings, or some or all of the 2030 Notes with a “make-whole” premium, in each case subject to the terms set forth in the 2030 Note Indenture. 2028 Notes On June 22, 2020, the Company issued $800.0 million aggregate principal amount of 4.50% Senior Notes due 2028. The 2028 Notes were issued pursuant to an indenture, dated as of June 22, 2020 (the “2028 Note Indenture”), among the Company, the guarantors party thereto and U.S. Bank National Association, as trustee. The 2028 Notes were issued at an issue price of 100.0% and bear interest at a rate of 4.50% per annum. Interest on the 2028 Notes is payable on January 1 and July 1 of each year, beginning on January 1, 2021. The 2028 Notes will mature on July 1, 2028. The Company may redeem some or all of the 2028 Notes at any time on or after July 1, 2023 for cash at the redemption prices set forth in the 2028 Note Indenture, plus accrued and unpaid interest to, but excluding, the redemption date. Prior to July 1, 2023, the Company may redeem up to 40% of the aggregate principal amount of the 2028 Notes in connection with certain equity offerings, or some or all of the 2028 Notes with a “make-whole” premium, in each case subject to the terms set forth in the 2028 Note Indenture. 2020 Credit Agreement On September 28, 2020, the Company entered into an agreement among the Company, as borrower, the lenders party thereto and JPMorgan Chase Bank, N.A., as administrative agent (the “Administrative Agent,” and such agreement, the “2020 Credit Agreement”), which amended and restated the Company’s existing credit facility, dated as of June 17, 2016 (as amended, supplemented or otherwise modified from time to time, the “2016 Credit Agreement”). The 2020 Credit Agreement provides for a $400.0 million senior secured five-year term loan facility and a $1.0 billion senior secured five-year revolving facility. The term and revolving facilities may be increased, at the Company’s option and under certain conditions, by up to an additional $1.0 billion in the aggregate plus additional amounts subject to the satisfaction of certain conditions, including a maximum secured leverage ratio. The term loan will be repaid in consecutive quarterly installments commencing December 31, 2020, plus a final payment due on September 28, 2025, and may be prepaid at any time without penalty or premium (other than applicable breakage costs) at the option of the Company. The revolving credit facility may be used for loans, and up to $75.0 million may be used for letters of credit. The revolving loans may be borrowed, repaid and re-borrowed until September 28, 2025, at which time all amounts borrowed must be repaid. On September 28, 2020, the Company drew down $400.0 million in term loans. The initial drawdown was used to refinance the outstanding amounts under the 2016 Credit Agreement. Additional amounts drawn down under the 2020 Credit Agreement will be used for general corporate purposes, including the funding of acquisitions, payment of capital expenditures and the repurchase of shares. The Company used a portion of the net proceeds from the issuance of the 2029 Notes to repay $100.0 million of the outstanding borrowings under the term loan facility in June 2021. The Company’s obligations under the 2020 Credit Agreement are guaranteed, on a secured basis, by certain existing and future direct and indirect U.S. subsidiaries. The Company’s obligations under the 2020 Credit Agreement and the guarantees of the subsidiary guarantors are secured by first priority security interests in substantially all of the assets of the Company and the subsidiary guarantors. The security and pledges are subject to certain exceptions. Loans under the 2020 Credit Agreement bear interest at a rate equal to, at the Company’s option, either (i) the greatest of: (x) the Wall Street Journal prime rate; (y) the average rate on Federal Reserve Board of New York rate plus 1/2 of 1%; and (z) and the adjusted LIBO rate (adjusted for statutory reserves) for a one-month interest period plus 1%, in each case plus a margin equal to between 0.125% and 1.25% depending on the Company’s consolidated leverage ratio as of the end of the four consecutive fiscal quarters most recently ended, or (ii) the adjusted LIBO rate (adjusted for statutory reserves) plus a margin equal to between 1.125% and 2.25%, depending on the Company’s leverage ratio as of the end of the four consecutive fiscal quarters most recently ended. The commitment fee payable on the unused portion of the revolving credit facility is equal to between 0.175% and 0.40% based on utilization of the revolving credit facility. The Company has also agreed to pay customary letter of credit fees. Interest Rate Swaps As of June 30, 2021, the Company had four fixed-for-floating interest rate swap contracts with a total notional value of $1.4 billion that mature through 2025. The Company pays base fixed rates on these swaps ranging from 2.13% to 3.04% and in return receives a floating Eurodollar base rate on 30-day notional borrowings. As a result of the payment under the then outstanding 2016 Credit Agreement term loan and revolving credit facility, the Company de-designated all of its interest rate swaps effective June 30, 2020. Accordingly, hedge accounting is not applicable, and subsequent changes to the fair value of the interest rate swaps are recorded in Other (expense) income, net. The amounts previously recorded in Accumulated other comprehensive loss are amortized into Interest expense, net over the terms of the hedged forecasted interest payments. As of June 30, 2021, $89.7 million is remaining in Accumulated other comprehensive loss, net. The interest rate swaps had negative unrealized fair values (liabilities) of $80.0 million and $109.2 million as of June 30, 2021 and December 31, 2020, respectively, of which $67.4 million and $78.1 million were recorded in Accumulated other comprehensive loss, net of tax effect, as of June 30, 2021 and December 31, 2020, respectively. See Note 12 — Fair Value Disclosures for the determination of the fair values of Company’s interest rate swaps.

Equity

Equity	6 Months Ended
	Jun. 30, 2021
Stockholders' Equity Note [Abstract]
Equity	Equity Share Repurchase Authorization In 2015, the Company’s Board of Directors (the “Board”) authorized a share repurchase program to repurchase up to $1.2 billion of the Company’s common stock. The Board authorized incremental share repurchases of up to an additional $300.0 million and $500.0 million of the Company’s common stock in February 2021 and April 2021, respectively. $0.3 billion remained available under the share repurchase program as of June 30, 2021. The Company may repurchase its common stock from time-to-time in amounts, at prices and in the manner that the Company deems appropriate, subject to the availability of stock, prevailing market conditions, the trading price of the stock, the Company’s financial performance and other conditions. Repurchases may be made through open market purchases (which may include repurchase plans designed to comply with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended), accelerated share repurchases, private transactions or other transactions and will be funded by cash on hand and borrowings. Repurchases may also be made from time-to-time in connection with the settlement of the Company’s stock-based compensation awards. See Note 15 — Subsequent Event for a discussion regarding an increase in the Company’s share repurchase authorization. The Company’s share repurchase activity is presented in the table below for the periods indicated. Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Number of shares repurchased (1) 3,094,706 5,999 5,369,416 423,706 Cash paid for repurchased shares (in thousands) (2) $ 684,900 $ 698 $ 1,083,350 $ 73,862 (1) The average purchase price for repurchased shares was $218.33 and $116.29 for the three months ended June 30, 2021 and 2020, respectively, and $202.28 and $150.72 for the six months ended June 30, 2021 and 2020, respectively. The repurchased shares during the three months ended June 30, 2021 included purchases for both stock-based compensation award settlements and open market purchases. All of the shares repurchased during the three months ended June 30, 2020 related to the settlement of the Company's stock-based compensation awards. The repurchased shares during the six months ended June 30, 2021 and 2020 included purchases for both stock-based compensation award settlements and open market purchases. (2) The cash paid for repurchased shares during the six months ended June 30, 2021 included $8.0 million of open market purchases with trade dates in December 2020 that settled in January 2021. There were $10.8 million of open market purchases with trade dates in June 2021 that settled in July 2021. The cash paid for repurchased shares during the six months ended June 30, 2020 included $10.0 million of open market purchases with trade dates in December 2019 that settled in January 2020. Accumulated Other Comprehensive Loss, net (“AOCL”) The tables below provide information about the changes in AOCL by component and the related amounts reclassified out of AOCL to income during the periods indicated (net of tax, in thousands) (1). Three Months Ended June 30, 2021 Interest Rate Defined Foreign Total Balance – March 31, 2021 $ (72,834) $ (9,206) $ (11,138) $ (93,178) Other comprehensive income activity during the period: Change in AOCL before reclassifications to income — — 4,639 4,639 Reclassifications from AOCL to income (2), (3) 5,457 104 — 5,561 Other comprehensive income for the period 5,457 104 4,639 10,200 Balance – June 30, 2021 $ (67,377) $ (9,102) $ (6,499) $ (82,978) Three Months Ended June 30, 2020 Interest Rate Defined Foreign Total Balance – March 31, 2020 $ (91,896) $ (8,505) $ (68,571) $ (168,972) Other comprehensive income (loss) activity during the period: Change in AOCL before reclassifications to income (9,935) — 23,817 13,882 Reclassifications from AOCL to income (2), (3) 12,835 80 — 12,915 Other comprehensive income for the period 2,900 80 23,817 26,797 Balance – June 30, 2020 $ (88,996) $ (8,425) $ (44,754) $ (142,175) Six Months Ended June 30, 2021 Interest Rate Defined Foreign Total Balance – December 31, 2020 $ (78,104) $ (9,309) $ (11,815) $ (99,228) Other comprehensive income activity during the period: Change in AOCL before reclassifications to income — — 5,316 5,316 Reclassifications from AOCL to income (2), (3) 10,727 207 — 10,934 Other comprehensive income for the period 10,727 207 5,316 16,250 Balance – June 30, 2021 $ (67,377) $ (9,102) $ (6,499) $ (82,978) Six Months Ended June 30, 2020 Interest Rate Defined Foreign Total Balance – December 31, 2019 $ (47,164) $ (8,584) $ (22,190) $ (77,938) Other comprehensive (loss) income activity during the period: Change in AOCL before reclassifications to income (56,989) — (22,564) (79,553) Reclassifications from AOCL to income (2), (3) 15,157 159 — 15,316 Other comprehensive (loss) income for the period (41,832) 159 (22,564) (64,237) Balance – June 30, 2020 $ (88,996) $ (8,425) $ (44,754) $ (142,175) (1) Amounts in parentheses represent debits (deferred losses). (2) $7.3 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net, for both of the three months ended June 30, 2021 and 2020. $14.3 million and $10.5 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net, for the six months ended June 30, 2021 and 2020, respectively. $10.3 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Other (expense) income, net for both the three and six months ended June 30, 2020. See Note 8 — Debt and Note 11 — Derivatives and Hedging for information regarding the cash flow hedges. (3) The reclassifications related to defined benefit pension plans were recorded in Other (expense) income, net.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision for income taxes for the three months ended June 30, 2021 and 2020 was an expense of $108.0 million and $3.9 million, respectively. The provision for income taxes for the six months ended June 30, 2021 and 2020 was an expense of $158.6 million and $25.6 million, respectively. The effective income tax rate was 28.5% and 6.6% for the three months ended June 30, 2021 and 2020, respectively. The effective income tax rate was 26.7% and 16.5% for the six months ended June 30, 2021 and 2020, respectively. In 2020, the Company completed intercompany sales of certain intellectual property. Approximately $28.3 million of tax benefits were recognized as a result for the three and six months ended June 30, 2020. These benefits represented the value of future tax deductions for amortization of the assets in the acquiring jurisdiction. No such benefits are included in 2021. This drove a significant increase in the effective income tax rate period over period. In addition, during the second quarter of 2021, the United Kingdom enacted legislation raising its corporate tax rate from 19% to 25% effective April 2023, which increased the Company’s effective income tax rate for the three and six months ended June 30, 2021. The Company had gross unrecognized tax benefits of $130.1 million on June 30, 2021 and $127.1 million on December 31, 2020. It is reasonably possible that gross unrecognized tax benefits will decrease by approximately $9.2 million within the next twelve months due to the anticipated closure of audits and the expiration of certain statutes of limitation.

Derivatives and Hedging

Derivatives and Hedging	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging	Derivatives and Hedging The Company enters into a limited number of derivative contracts to mitigate the cash flow risk associated with changes in interest rates on variable-rate debt and changes in foreign exchange rates on forecasted foreign currency transactions. The Company accounts for its outstanding derivative contracts in accordance with FASB ASC Topic 815, which requires all derivatives, including derivatives designated as accounting hedges, to be recorded on the balance sheet at fair value. The tables below provide information regarding the Company’s outstanding derivative contracts as of the dates indicated (in thousands, except for number of contracts). June 30, 2021 Derivative Contract Type Number of Notional Fair Value Balance Unrealized Interest rate swaps (1) 4 $ 1,400,000 $ (48,700) Other liabilities $ (67,377) (31,341) Accrued liabilities Foreign currency forwards (2) 26 222,893 (138) Accrued liabilities — Total 30 $ 1,622,893 $ (80,179) $ (67,377) December 31, 2020 Derivative Contract Type Number of Contracts Notional Fair Value Balance Unrealized Interest rate swaps (1) 4 $ 1,400,000 $ (74,289) Other liabilities $ (78,104) (34,886) Accrued liabilities Foreign currency forwards (2) 163 430,063 (1,514) Accrued liabilities — Total 167 $ 1,830,063 $ (110,689) $ (78,104) (1) As a result of the payment under the then outstanding 2016 Credit Agreement term loan and revolving credit facility, the Company de-designated all of its interest rate swaps effective June 30, 2020. Accordingly, hedge accounting is not applicable, and subsequent changes to fair value of the interest rate swaps are recorded in Other (expense) income, net. The amounts previously recorded in Accumulated other comprehensive loss are amortized into Interest expense, net over the terms of the hedged forecasted interest payments. See Note 8 — Debt provides additional information regarding the Company’s interest rate swap contracts. (2) The Company has foreign exchange transaction risk because it typically enters into transactions in the normal course of business that are denominated in foreign currencies that differ from the local functional currency. The Company enters into short-term foreign currency forward exchange contracts to mitigate the cash flow risk associated with changes in foreign currency rates on forecasted foreign currency transactions. These contracts are accounted for at fair value with realized and unrealized gains and losses recognized in Other (expense) income, net because the Company does not designate these contracts as hedges for accounting purposes. All of the outstanding foreign currency forward exchange contracts at June 30, 2021 matured before July 31, 2021. (3) See Note 12 — Fair Value Disclosures for the determination of the fair values of these instruments. At June 30, 2021, all of the Company’s derivative counterparties were investment grade financial institutions. The Company did not have any collateral arrangements with its derivative counterparties and none of the derivative contracts contained credit-risk related contingent features. The table below provides information regarding amounts recognized in the accompanying Condensed Consolidated Statements of Operations for derivative contracts for the periods indicated (in thousands). Three Months Ended Six Months Ended June 30, June 30, Amount recorded in: 2021 2020 2021 2020 Interest expense, net (1) $ 7,283 $ 7,322 $ 14,315 $ 10,514 Other expense (income), net (2) 1,494 9,715 (14,329) 22,314 Total (income) expense, net $ 8,777 $ 17,037 $ (14) $ 32,828 (1) Consists of interest expense from interest rate swap contracts.

Fair Value Disclosures

Fair Value Disclosures	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value Disclosures The Company’s financial instruments include cash equivalents, fees receivable from customers, accounts payable and accrued liabilities, all of which are normally short-term in nature. The Company believes that the carrying amounts of these financial instruments reasonably approximate their fair values due to their short-term nature. The Company’s financial instruments also include its outstanding variable-rate borrowings under the 2020 Credit Agreement. The Company believes that the carrying amounts of its variable-rate borrowings reasonably approximate their fair values because the rates of interest on those borrowings reflect current market rates of interest for similar instruments with comparable maturities. The Company enters into a limited number of derivatives transactions but does not enter into repurchase agreements, securities lending transactions or master netting arrangements. Receivables or payables that result from derivatives transactions are recorded gross in the Company’s consolidated balance sheets. FASB ASC Topic 820 provides a framework for the measurement of fair value and a valuation hierarchy based on the transparency of inputs used in the valuation of assets and liabilities. Classification within the valuation hierarchy is based on the lowest level of input that is significant to the resulting fair value measurement. The valuation hierarchy contains three levels. Level 1 measurements consist of quoted prices in active markets for identical assets or liabilities. Level 2 measurements include significant other observable inputs such as quoted prices for similar assets or liabilities in active markets; identical assets or liabilities in inactive markets; observable inputs such as interest rates and yield curves; and other market-corroborated inputs. Level 3 measurements include significant unobservable inputs such as internally-created valuation models. The Company does not currently utilize Level 3 valuation inputs to remeasure any of its assets or liabilities. However, Level 3 inputs may be used by the Company in its required annual impairment review of goodwill. Information regarding the periodic assessment of the Company’s goodwill is included in Note 3 — Goodwill and Intangible Assets. The Company does not typically transfer assets or liabilities between different levels of the valuation hierarchy. The table below presents the fair values of certain financial assets and liabilities (in thousands). Description June 30, December 31, Assets: Values based on Level 1 inputs: Deferred compensation plan assets (1) $ 8,642 $ 2,589 Total Level 1 inputs 8,642 2,589 Values based on Level 2 inputs: Deferred compensation plan assets (1) 90,946 85,932 Foreign currency forward contracts (2) 44 885 Total Level 2 inputs 90,990 86,817 Total Assets $ 99,632 $ 89,406 Liabilities: Values based on Level 2 inputs: Deferred compensation plan liabilities (1) $ 106,390 $ 94,538 Foreign currency forward contracts (2) 182 2,399 Interest rate swap contracts (3) 80,041 109,175 Total Level 2 inputs 186,613 206,112 Total Liabilities $ 186,613 $ 206,112 (1) The Company has a deferred compensation plan for the benefit of certain highly compensated officers, managers and other key employees. The assets consist of investments in money market funds, mutual funds and company-owned life insurance contracts, which are valued based on Level 1 or Level 2 inputs. The related deferred compensation plan liabilities are recorded at fair value, or the estimated amount needed to settle the liability, which the Company considers to be a Level 2 input. (2) The Company enters into foreign currency forward exchange contracts to hedge the effects of adverse fluctuations in foreign currency exchange rates (see Note 11 — Derivatives and Hedging). Valuation of these contracts is based on observable foreign currency exchange rates in active markets, which the Company considers to be a Level 2 input. (3) The Company has interest rate swap contracts that hedge the risk of variability from interest payments on its borrowings (see Note 8 — Debt). The fair values of interest rate swaps are based on mark-to-market valuations prepared by a third-party broker. Those valuations are based on observable interest rates from recently executed market transactions and other observable market data, which the Company considers to be Level 2 inputs. The Company independently corroborates the reasonableness of the valuations prepared by the third-party broker by using an electronic quotation service. Assets and liabilities measured at fair value on a non-recurring basis See Note 2 — Acquisition for fair value measurements of certain assets and liabilities recorded at fair value on a non-recurring basis. The table below presents the carrying amounts (net of deferred financing costs) and fair values of financial instruments that are not recorded at fair value in the Company’s Condensed Consolidated Balance Sheets (in thousands). The estimated fair value of the financial instruments was derived from quoted market prices provided by an independent dealer, which the Company considers to be a Level 2 input. Carrying Amount Fair Value June 30, December 31, June 30, December 31, Description 2021 2020 2021 2020 2028 Notes $ 791,302 $ 790,783 $ 846,248 $ 846,296 2029 Notes 592,742 — 611,418 — 2030 Notes 791,087 790,690 819,608 843,800 Total $ 2,175,131 $ 1,581,473 $ 2,277,274 $ 1,690,096

Contingencies

Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Legal Matters. The Company is involved in legal proceedings and litigation arising in the ordinary course of business. A provision is recorded for pending litigation in the Company’s consolidated financial statements when it is determined that an unfavorable outcome is probable and the amount of the loss can be reasonably estimated. The Company believes that the potential liability, if any, in excess of amounts already accrued from all proceedings, claims and litigation will not have a material effect on the its financial position, cash flows or results of operations when resolved in a future period. Indemnifications. The Company has various agreements that may obligate it to indemnify the other party with respect to certain matters. Generally, these indemnification clauses are included in contracts arising in the normal course of business under which the Company customarily agrees to hold the other party harmless against losses arising from a breach of representations related to matters such as title to assets sold and licensed or certain intellectual property rights. It is not possible to predict the maximum potential amount of future payments under these indemnification agreements due to the conditional nature of the Company’s obligations and the unique facts of each particular agreement. Historically, payments made by the Company under these agreements have not been material. As of June 30, 2021, the Company did not have any material payment obligations under any such indemnification agreements.

Leases

Leases	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Leases	Leases The Company’s leasing activities are primarily for facilities under cancelable and non-cancelable lease agreements expiring during 2021 and through 2038. These facilities support our executive and administrative activities, sales, systems support, operations, and other functions. The Company also has leases for office equipment and other assets, which are not significant. Certain of these lease agreements include (i) renewal options to extend the lease term for up to five years and/or (ii) options to terminate the agreement within one year. Additionally, certain of the Company’s lease agreements provide standard recurring escalations of lease payments for, among other things, increases in a lessor’s maintenance costs and taxes. Under some lease agreements, the Company may be entitled to allowances, free rent, lessor-financed tenant improvements and other incentives. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants. The Company subleases certain office space that it does not intend to occupy. Such sublease arrangements expire during 2021 and through 2032 and primarily relate to facilities in Arlington, Virginia. Certain of the Company’s sublease agreements: (i) include renewal and termination options; (ii) provide for customary escalations of lease payments in the normal course of business; and (iii) grant the subtenant certain allowances, free rent, Gartner-financed tenant improvements and other incentives. All of the Company’s leasing and subleasing activity is recognized in Selling, general and administrative expense in the accompanying Condensed Consolidated Statements of Operations. The table below presents the Company’s net lease cost and certain other information related to the Company’s leasing activities as of and for the periods indicated (dollars in thousands). Three Months Ended Six Months Ended June 30, June 30, Description: 2021 2020 2021 2020 Operating lease cost (1) $ 32,620 $ 35,173 $ 65,485 $ 73,134 Variable lease cost (2) 4,121 3,973 8,423 8,376 Sublease income (10,584) (10,719) (20,923) (21,810) Total lease cost, net (3) $ 26,157 $ 28,427 $ 52,985 $ 59,700 Cash paid for amounts included in the measurement of operating $ 35,324 $ 34,026 $ 70,251 $ 68,962 Cash receipts from sublease arrangements $ 10,364 $ 9,503 $ 20,459 $ 18,920 Right-of-use assets obtained in exchange for new operating lease $ 2,248 $ 3,616 $ 9,294 $ 18,535 (1) Included in operating lease cost was $10.7 million and $10.6 million for the three months ended June 30, 2021 and 2020, respectively, and $21.1 million and $21.2 million for the six months ended June 30, 2021 and 2020, respectively, for costs related to subleasing activities. (2) These amounts are primarily variable lease and nonlease costs that were not fixed at the lease commencement date or are dependent on something other than an index or a rate. (3) The Company did not capitalize any operating lease costs during any of the periods presented. The table below indicates where the discounted operating lease payments from the above table are classified in the accompanying Condensed Consolidated Balance Sheets (in thousands). June 30, December 31, Description: 2021 2020 Accounts payable and accrued liabilities $ 86,381 $ 83,995 Operating leases - liabilities 745,108 780,166 Total operating lease liabilities per the Condensed Consolidated Balance Sheets $ 831,489 $ 864,161
Leases	Leases The Company’s leasing activities are primarily for facilities under cancelable and non-cancelable lease agreements expiring during 2021 and through 2038. These facilities support our executive and administrative activities, sales, systems support, operations, and other functions. The Company also has leases for office equipment and other assets, which are not significant. Certain of these lease agreements include (i) renewal options to extend the lease term for up to five years and/or (ii) options to terminate the agreement within one year. Additionally, certain of the Company’s lease agreements provide standard recurring escalations of lease payments for, among other things, increases in a lessor’s maintenance costs and taxes. Under some lease agreements, the Company may be entitled to allowances, free rent, lessor-financed tenant improvements and other incentives. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants. The Company subleases certain office space that it does not intend to occupy. Such sublease arrangements expire during 2021 and through 2032 and primarily relate to facilities in Arlington, Virginia. Certain of the Company’s sublease agreements: (i) include renewal and termination options; (ii) provide for customary escalations of lease payments in the normal course of business; and (iii) grant the subtenant certain allowances, free rent, Gartner-financed tenant improvements and other incentives. All of the Company’s leasing and subleasing activity is recognized in Selling, general and administrative expense in the accompanying Condensed Consolidated Statements of Operations. The table below presents the Company’s net lease cost and certain other information related to the Company’s leasing activities as of and for the periods indicated (dollars in thousands). Three Months Ended Six Months Ended June 30, June 30, Description: 2021 2020 2021 2020 Operating lease cost (1) $ 32,620 $ 35,173 $ 65,485 $ 73,134 Variable lease cost (2) 4,121 3,973 8,423 8,376 Sublease income (10,584) (10,719) (20,923) (21,810) Total lease cost, net (3) $ 26,157 $ 28,427 $ 52,985 $ 59,700 Cash paid for amounts included in the measurement of operating $ 35,324 $ 34,026 $ 70,251 $ 68,962 Cash receipts from sublease arrangements $ 10,364 $ 9,503 $ 20,459 $ 18,920 Right-of-use assets obtained in exchange for new operating lease $ 2,248 $ 3,616 $ 9,294 $ 18,535 (1) Included in operating lease cost was $10.7 million and $10.6 million for the three months ended June 30, 2021 and 2020, respectively, and $21.1 million and $21.2 million for the six months ended June 30, 2021 and 2020, respectively, for costs related to subleasing activities. (2) These amounts are primarily variable lease and nonlease costs that were not fixed at the lease commencement date or are dependent on something other than an index or a rate. (3) The Company did not capitalize any operating lease costs during any of the periods presented. The table below indicates where the discounted operating lease payments from the above table are classified in the accompanying Condensed Consolidated Balance Sheets (in thousands). June 30, December 31, Description: 2021 2020 Accounts payable and accrued liabilities $ 86,381 $ 83,995 Operating leases - liabilities 745,108 780,166 Total operating lease liabilities per the Condensed Consolidated Balance Sheets $ 831,489 $ 864,161

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Event	Subsequent EventOn July 29, 2021, the Company’s Board of Directors authorized incremental share repurchases of up to an additional $800 million of Gartner’s common stock. This authorization is in addition to the previously authorized repurchases of up to $2.0 billion, which as of the end of July 2021 had approximately $231 million remaining.

Business and Basis of Present_2

Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Segments	Segments . Gartner delivers its products and services globally through three business segments: Research, Conferences and Consulting. Revenues and other financial information for our segments are discussed in Note 7 — Segment Information.
Basis of presentation	Basis of presentation . The accompanying interim Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”), as defined in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 270 for interim financial information and with the applicable instructions of U.S. Securities and Exchange Commission (“SEC”) Rule 10-01 of Regulation S-X on Form 10-Q, and should be read in conjunction with the consolidated financial statements and related notes of the Company in its Annual Report on Form 10-K for the year ended December 31, 2020.
Principles of consolidation	Principles of consolidation . The accompanying interim Condensed Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated.
Use of estimates	Use of estimates . The preparation of the accompanying interim Condensed Consolidated Financial Statements requires management to make estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities, and reported amounts of revenues and expenses. Such estimates include the valuation of fees receivable, goodwill, intangible assets and other long-lived assets, as well as tax accruals and other liabilities. In addition, estimates are used in revenue recognition, income tax expense or benefit, performance-based compensation charges, depreciation and amortization. Management believes its use of estimates in these interim Condensed Consolidated Financial Statements to be reasonable. Management continually evaluates and revises its estimates using historical experience and other factors, including the general economic environment and actions it may take in the future. Management adjusts these estimates when facts and circumstances dictate. However, these estimates may involve significant uncertainties and judgments and cannot be determined with precision. In addition, these estimates are based on management’s best judgment at a point in time. As a result, differences between estimates and actual results could be material and would be reflected in the Company’s consolidated financial statements in future periods.
Cash and cash equivalents and restricted cash	Cash and cash equivalents and restricted cash. For the six months ended June 30, 2021, the end of period cash and cash equivalents and restricted cash balance of $800.5 million in the accompanying Condensed Consolidated Statements of Cash Flows consisted of $796.3 million of cash and cash equivalents and $4.2 million of restricted cash. The restricted cash was classified in Other Assets in the accompanying Condensed Consolidated Balance Sheets as of June 30, 2021.
Revenue recognition	Revenue recognition. Revenue is recognized in accordance with the requirements of FASB ASC Topic 606, Revenue from Contracts with Customers
Adoption of new accounting standards	Adoption of new accounting standards. The Company adopted the accounting standard described below during the six months ended June 30, 2021. Simplifying the Accounting for Income Taxes — In December 2019, the FASB issued ASU No. 2019-12, Income Taxes—Simplifying the Accounting for Income Taxes (“ASU No. 2019-12”). ASU No. 2019-12 provides new guidance to simplify the accounting for income taxes in certain areas, changes the accounting for select income tax transactions and makes minor ASC improvements. Gartner adopted ASU No. 2019-12 on January 1, 2021. The adoption of ASU No. 2019-12 did not have a material impact on the Company’s Condensed Consolidated Financial Statements. Accounting standards issued but not yet adopted. The FASB has issued accounting standards that have not yet become effective and may impact the Company’s consolidated financial statements or related disclosures in future periods. Those standards and their potential impact are discussed below. Accounting standard effective immediately upon voluntary election by Gartner Reference Rate Reform — In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform—Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU No. 2020-04”). ASU No. 2020-04 provides that an entity can elect not to apply certain required modification accounting in U.S. GAAP to contracts where all changes to the critical terms relate to reference rate reform (e.g., the expected discontinuance of LIBOR and the transition to an alternative reference interest rate, etc.). In addition, the rule provides optional expedients and exceptions that enable entities to continue to apply hedge accounting for hedging relationships where one or more of the critical terms change due to reference rate reform. The rule became effective for all entities as of March 12, 2020 and will generally no longer be available to apply after December 31, 2022. The Company is currently evaluating the potential impact of ASU No. 2020-04 on its consolidated financial statements, including the rule’s potential impact on any debt modifications or other contractual changes in the future that may result from reference rate reform.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes to the carrying amount of goodwill by reporting unit	The table below presents changes to the carrying amount of goodwill by segment during the six months ended June 30, 2021 (in thousands). Research Conferences Consulting Total Balance at December 31, 2020 (1) $ 2,664,732 $ 184,091 $ 96,724 $ 2,945,547 Additions due to an acquisition (2) 11,172 — — 11,172 Foreign currency translation impact (1,398) (20) 165 (1,253) Balance at June 30, 2021 (1) $ 2,674,506 $ 184,071 $ 96,889 $ 2,955,466 (1) The Company does not have any accumulated goodwill impairment losses. (2) The additions were due to the acquisition of Pulse on June 17, 2021. See Note 2 — Acquisition for additional information.
Schedule of amortizable intangible assets	The tables below present reconciliations of the carrying amounts of the Company’s finite-lived intangible assets as of the dates indicated (in thousands). June 30, 2021 Customer Software Content Other Total Gross cost at December 31, 2020 $ 1,154,210 $ 110,597 $ 3,965 $ 10,614 $ 1,279,386 Additions due to an acquisition (1) 7,980 11,200 — 280 19,460 Intangible assets fully amortized (17,788) (60,631) (3,965) — (82,384) Foreign currency translation impact 7,895 226 — — 8,121 Gross cost 1,152,297 61,392 — 10,894 1,224,583 Accumulated amortization (2) (414,460) (30,394) — (4,250) (449,104) Balance at June 30, 2021 $ 737,837 $ 30,998 $ — $ 6,644 $ 775,479 December 31, 2020 Customer Software Content Other Total Gross cost $ 1,154,210 $ 110,597 $ 3,965 $ 10,614 $ 1,279,386 Accumulated amortization (2) (381,776) (83,320) (3,595) (3,697) (472,388) Balance at December 31, 2020 $ 772,434 $ 27,277 $ 370 $ 6,917 $ 806,998 (1) The additions were due to the acquisition of Pulse on June 17, 2021. See Note 2 — Acquisition for additional information. (2) Finite-lived intangible assets are amortized using the straight-line method over the following periods: Customer relationships—6 to 13 years; Software—3 to 7 years; Content—2 to 3 years; and Other—2 to 11 years.
Schedule of estimated future amortization expense by year	The estimated future amortization expense by year for finite-lived intangible assets is presented in the table below (in thousands). 2021 (remaining six months) $ 52,600 2022 101,768 2023 101,752 2024 94,540 2025 84,001 Thereafter 340,818 $ 775,479

Revenue and Related Matters (Ta

Revenue and Related Matters (Tables)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue by Reportable Segment	Disaggregated Revenue — The Company’s disaggregated revenue by reportable segment is presented in the tables below for the periods indicated (in thousands). By Primary Geographic Market (1) Three Months Ended June 30, 2021 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 646,432 $ 40,328 $ 59,605 $ 746,365 Europe, Middle East and Africa 236,756 14,468 35,459 286,683 Other International 120,050 3,383 10,838 134,271 Total revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Three Months Ended June 30, 2020 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 573,245 $ 317 $ 58,017 $ 631,579 Europe, Middle East and Africa 196,854 — 30,114 226,968 Other International 105,230 — 9,358 114,588 Total revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Six Months Ended June 30, 2021 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 1,277,765 $ 59,927 $ 117,091 $ 1,454,783 Europe, Middle East and Africa 466,957 17,181 65,821 $ 549,959 Other International 238,248 5,873 22,494 $ 266,615 Total revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Six Months Ended June 30, 2020 Primary Geographic Market Research Conferences Consulting Total United States and Canada $ 1,163,400 $ 6,297 $ 112,181 $ 1,281,878 Europe, Middle East and Africa 402,794 2,147 60,196 465,137 Other International 218,426 5,743 20,842 245,011 Total revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 (1) Revenue is reported based on where the sale is fulfilled.
Schedule of Disaggregation of Revenue	By Timing of Revenue Recognition Three Months Ended June 30, 2021 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 916,754 $ — $ 85,989 $ 1,002,743 Transferred at a point in time (2) 86,484 58,179 19,913 164,576 Total revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Three Months Ended June 30, 2020 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 810,564 $ — $ 68,630 $ 879,194 Transferred at a point in time (2) 64,765 317 28,859 93,941 Total revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Six Months Ended June 30, 2021 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 1,810,841 $ — $ 170,331 $ 1,981,172 Transferred at a point in time (2) 172,129 82,981 35,075 290,185 Total revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Six Months Ended June 30, 2020 Timing of Revenue Recognition Research Conferences Consulting Total Transferred over time (1) $ 1,639,776 $ — $ 150,038 $ 1,789,814 Transferred at a point in time (2) 144,844 14,187 43,181 202,212 Total revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 (1) Research revenues were recognized in connection with performance obligations that were satisfied over time using a time-elapsed output method to measure progress. Consulting revenues were recognized over time using labor hours as an input measurement basis. (2) The revenues in this category were recognized in connection with performance obligations that were satisfied at the point in time that the contractual deliverables were provided to the customer.
Schedule for Contract with Customer, Asset and Liability	The table below provides information regarding certain of the Company’s balance sheet accounts that pertain to its contracts with customers (in thousands). June 30, December 31, 2021 2020 Assets: Fees receivable, gross (1) $ 1,110,562 $ 1,251,508 Contract assets recorded in Prepaid expenses and other current assets (2) $ 22,637 $ 14,440 Contract liabilities: Deferred revenues (current liability) (3) $ 2,152,043 $ 1,974,548 Non-current deferred revenues recorded in Other liabilities (3) 31,826 26,754 Total contract liabilities $ 2,183,869 $ 2,001,302 (1) Fees receivable represent an unconditional right to payment from the Company’s customers and include both billed and unbilled amounts. (2) Contract assets represent recognized revenue for which the Company does not have an unconditional right to payment as of the balance sheet date because the project may be subject to a progress billing milestone or some other billing restriction. (3) Deferred revenues represent amounts (i) for which the Company has received an upfront customer payment or (ii) that pertain to recognized fees receivable. Both situations occur before the completion of the Company’s performance obligation(s).

Computation of Earnings Per S_2

Computation of Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Schedule of basic and diluted (loss) earnings per share calculations	The table below sets forth the calculation of basic and diluted income per share for the periods indicated (in thousands, except per share data). Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Numerator: Net income used for calculating basic and diluted income per share $ 271,236 $ 55,077 $ 435,336 $ 130,174 Denominator: Weighted average common shares used in the calculation of basic income per share 85,712 89,323 87,032 89,271 Dilutive effect of outstanding awards associated with stock-based compensation plans (1) 877 457 889 696 Shares used in the calculation of diluted income per share 86,589 89,780 87,921 89,967 Basic income per share $ 3.16 $ 0.62 $ 5.00 $ 1.46 Diluted income per share $ 3.13 $ 0.61 $ 4.95 $ 1.45 (1) Certain potential shares of common stock were not included in the computation of diluted income per share because the effect would have been anti-dilutive. For the three and six months ended June 30, 2021, approximately 0.1 million shares of common stock equivalents were excluded for both periods from the calculation of diluted income per share because they were anti-dilutive. For the three and six months ended June 30, 2020, approximately 1.3 million and 0.8 million shares of common stock equivalents, respectively, were excluded because of their anti-dilutive effect.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of stock-based compensation expense by award type	The tables below summarize the Company’s stock-based compensation expense by award type and expense category line item during the periods indicated (in millions). Three Months Ended Six Months Ended June 30, June 30, Award type 2021 2020 2021 2020 Stock appreciation rights $ 2.0 $ 1.9 $ 4.0 $ 3.6 Restricted stock units (2) 24.0 13.6 57.9 36.8 Common stock equivalents 0.2 0.2 0.4 0.4 Total (1) $ 26.2 $ 15.7 $ 62.3 $ 40.8
Schedule of stock-based compensation expense by expense category	Three Months Ended Six Months Ended June 30, June 30, Expense category line item 2021 2020 2021 2020 Cost of services and product development $ 8.0 $ 7.1 $ 21.7 $ 19.2 Selling, general and administrative 18.2 8.6 40.6 21.6 Total (1) (2) $ 26.2 $ 15.7 $ 62.3 $ 40.8 (1) Includes charges of $11.3 million and $5.2 million during the three months ended June 30, 2021 and 2020, respectively, and $32.8 million and $16.8 million during the six months ended June 30, 2021 and 2020, respectively, for awards to retirement-eligible employees. Those awards vest on an accelerated basis. (2) On February 5, 2020, prior to the COVID-19 related shutdown in the U.S., the Compensation Committee (“Committee”) of the Board of Directors of the Company established performance measures for the performance-based restricted stock units (the “PSUs”) awarded to the Company’s executive officers in 2020 under the Plan. Based on preliminary corporate performance results for the 2020 performance measures, the 2020 PSUs would have been earned at 50% of target. However,

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule of segment reporting information, by segment	The tables below present information about the Company’s reportable segments for the periods indicated (in thousands). Three Months Ended June 30, 2021 Research Conferences Consulting Consolidated Revenues $ 1,003,238 $ 58,179 $ 105,902 $ 1,167,319 Gross contribution 742,131 42,602 42,770 827,503 Corporate and other expenses (552,789) Operating income $ 274,714 Three Months Ended June 30, 2020 Research Conferences Consulting Consolidated Revenues $ 875,329 $ 317 $ 97,489 $ 973,135 Gross contribution 632,624 (11,230) 33,542 654,936 Corporate and other expenses (555,285) Operating income $ 99,651 Six Months Ended June 30, 2021 Research Conferences Consulting Consolidated Revenues $ 1,982,970 $ 82,981 $ 205,406 $ 2,271,357 Gross contribution 1,466,503 56,498 81,868 1,604,869 Corporate and other expenses (1,104,743) Operating income $ 500,126 Six Months Ended June 30, 2020 Research Conferences Consulting Consolidated Revenues $ 1,784,620 $ 14,187 $ 193,219 $ 1,992,026 Gross contribution 1,286,094 (17,290) 62,925 1,331,729 Corporate and other expenses (1,107,359) Operating income $ 224,370
Schedule of reconciliation of segment gross contribution to net income (loss)	The table below provides a reconciliation of total segment gross contribution to net income for the periods indicated (in thousands). Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Total segment gross contribution $ 827,503 $ 654,936 $ 1,604,869 $ 1,331,729 Costs and expenses: Cost of services and product development - unallocated (1) 10,986 4,352 18,781 3,532 Selling, general and administrative 488,496 494,840 975,751 991,479 Depreciation and amortization 52,005 53,936 108,269 108,632 Acquisition and integration charges 1,302 2,157 1,942 3,716 Operating income 274,714 99,651 500,126 224,370 Interest expense and other, net (31,072) (40,695) (41,731) (68,559) Gain on event cancellation insurance claims 135,545 — 135,545 — Less: Provision for income taxes 107,951 3,879 158,604 25,637 Net income $ 271,236 $ 55,077 $ 435,336 $ 130,174 (1) The unallocated amounts consist of certain bonus and fringe costs recorded in consolidated Cost of services and product development that are not allocated to segment expense. The Company’s policy is to allocate bonuses to segments at 100% of a segment employee’s target bonus. Amounts above or below 100% are absorbed by corporate.

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of debt	The Company’s total outstanding borrowings are summarized in the table below (in thousands). June 30, December 31, Description 2021 2020 2020 Credit Agreement - Term loan facility (1) $ 290,000 $ 395,000 2020 Credit Agreement - Revolving credit facility (1), (2) — 5,000 Senior Notes due 2028 (“2028 Notes”) (3) 800,000 800,000 Senior Notes due 2029 (“2029 Notes”) (4) 600,000 — Senior Notes due 2030 (“2030 Notes”) (5) 800,000 800,000 Other (6) 5,790 6,046 Principal amount outstanding (7) 2,495,790 2,006,046 Less: deferred financing fees (8) (32,614) (27,245) Net balance sheet carrying amount $ 2,463,176 $ 1,978,801 (1) The contractual annualized interest rate as of June 30, 2021 on the 2020 Credit Agreement Term loan facility and the revolving credit facility was 1.50%, which consisted of a floating Eurodollar base rate of 0.125% plus a margin of 1.375%. However, the Company has interest rate swap contracts that effectively convert the floating Eurodollar base rates on outstanding amounts to a fixed base rate. (2) The Company had approximately $1.0 billion of available borrowing capacity on the 2020 Credit Agreement revolver (not including the expansion feature) as of June 30, 2021. (3) Consists of $800.0 million principal amount of 2028 Notes outstanding. The 2028 Notes bear interest at a fixed rate of 4.50% and mature on July 1, 2028. (4) Consists of $600.0 million principal amount of 2029 Notes outstanding. The 2029 Notes bear interest at a fixed rate of 3.625% and mature on June 15, 2029. (5) Consists of $800.0 million principal amount of 2030 Notes outstanding. The 2030 Notes bear interest at a fixed rate of 3.75% and mature on October 1, 2030. (6) Consists of two State of Connecticut economic development loans. One of the loans originated in 2012, has a 10-year maturity and the outstanding balance of $0.8 million as of June 30, 2021 bears interest at a fixed rate of 3.00%. The second loan, originated in 2019, has a 10-year maturity and bears interest at a fixed rate of 1.75%. Both of these loans may be repaid at any time by the Company without penalty. (7) The weighted average annual effective rate on the Company’s outstanding debt for the three and six months ended June 30, 2021, including the effects of its interest rate swaps discussed below, was 4.96% and 4.99%, respectively. (8) Deferred financing fees are being amortized to Interest expense, net over the term of the related debt obligation.

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2021
Stockholders' Equity Note [Abstract]
Schedule of share repurchase activity	The Company’s share repurchase activity is presented in the table below for the periods indicated. Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Number of shares repurchased (1) 3,094,706 5,999 5,369,416 423,706 Cash paid for repurchased shares (in thousands) (2) $ 684,900 $ 698 $ 1,083,350 $ 73,862 (1) The average purchase price for repurchased shares was $218.33 and $116.29 for the three months ended June 30, 2021 and 2020, respectively, and $202.28 and $150.72 for the six months ended June 30, 2021 and 2020, respectively. The repurchased shares during the three months ended June 30, 2021 included purchases for both stock-based compensation award settlements and open market purchases. All of the shares repurchased during the three months ended June 30, 2020 related to the settlement of the Company's stock-based compensation awards. The repurchased shares during the six months ended June 30, 2021 and 2020 included purchases for both stock-based compensation award settlements and open market purchases. (2) The cash paid for repurchased shares during the six months ended June 30, 2021 included $8.0 million of open market purchases with trade dates in December 2020 that settled in January 2021. There were $10.8 million of open market purchases with trade dates in June 2021 that settled in July 2021. The cash paid for repurchased shares during the six months ended June 30, 2020 included $10.0 million of open market purchases with trade dates in December 2019 that settled in January 2020.
Schedule of the changes in Accumulated Other Comprehensive (Loss) Income by component (net of tax)	The tables below provide information about the changes in AOCL by component and the related amounts reclassified out of AOCL to income during the periods indicated (net of tax, in thousands) (1). Three Months Ended June 30, 2021 Interest Rate Defined Foreign Total Balance – March 31, 2021 $ (72,834) $ (9,206) $ (11,138) $ (93,178) Other comprehensive income activity during the period: Change in AOCL before reclassifications to income — — 4,639 4,639 Reclassifications from AOCL to income (2), (3) 5,457 104 — 5,561 Other comprehensive income for the period 5,457 104 4,639 10,200 Balance – June 30, 2021 $ (67,377) $ (9,102) $ (6,499) $ (82,978) Three Months Ended June 30, 2020 Interest Rate Defined Foreign Total Balance – March 31, 2020 $ (91,896) $ (8,505) $ (68,571) $ (168,972) Other comprehensive income (loss) activity during the period: Change in AOCL before reclassifications to income (9,935) — 23,817 13,882 Reclassifications from AOCL to income (2), (3) 12,835 80 — 12,915 Other comprehensive income for the period 2,900 80 23,817 26,797 Balance – June 30, 2020 $ (88,996) $ (8,425) $ (44,754) $ (142,175) Six Months Ended June 30, 2021 Interest Rate Defined Foreign Total Balance – December 31, 2020 $ (78,104) $ (9,309) $ (11,815) $ (99,228) Other comprehensive income activity during the period: Change in AOCL before reclassifications to income — — 5,316 5,316 Reclassifications from AOCL to income (2), (3) 10,727 207 — 10,934 Other comprehensive income for the period 10,727 207 5,316 16,250 Balance – June 30, 2021 $ (67,377) $ (9,102) $ (6,499) $ (82,978) Six Months Ended June 30, 2020 Interest Rate Defined Foreign Total Balance – December 31, 2019 $ (47,164) $ (8,584) $ (22,190) $ (77,938) Other comprehensive (loss) income activity during the period: Change in AOCL before reclassifications to income (56,989) — (22,564) (79,553) Reclassifications from AOCL to income (2), (3) 15,157 159 — 15,316 Other comprehensive (loss) income for the period (41,832) 159 (22,564) (64,237) Balance – June 30, 2020 $ (88,996) $ (8,425) $ (44,754) $ (142,175) (1) Amounts in parentheses represent debits (deferred losses). (2) $7.3 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net, for both of the three months ended June 30, 2021 and 2020. $14.3 million and $10.5 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Interest expense, net, for the six months ended June 30, 2021 and 2020, respectively. $10.3 million of the reclassifications related to interest rate swaps (cash flow hedges) were recorded in Other (expense) income, net for both the three and six months ended June 30, 2020. See Note 8 — Debt and Note 11 — Derivatives and Hedging for information regarding the cash flow hedges.

Derivatives and Hedging (Tables

Derivatives and Hedging (Tables)	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of information regarding outstanding derivative contracts	The tables below provide information regarding the Company’s outstanding derivative contracts as of the dates indicated (in thousands, except for number of contracts). June 30, 2021 Derivative Contract Type Number of Notional Fair Value Balance Unrealized Interest rate swaps (1) 4 $ 1,400,000 $ (48,700) Other liabilities $ (67,377) (31,341) Accrued liabilities Foreign currency forwards (2) 26 222,893 (138) Accrued liabilities — Total 30 $ 1,622,893 $ (80,179) $ (67,377) December 31, 2020 Derivative Contract Type Number of Contracts Notional Fair Value Balance Unrealized Interest rate swaps (1) 4 $ 1,400,000 $ (74,289) Other liabilities $ (78,104) (34,886) Accrued liabilities Foreign currency forwards (2) 163 430,063 (1,514) Accrued liabilities — Total 167 $ 1,830,063 $ (110,689) $ (78,104) (1) As a result of the payment under the then outstanding 2016 Credit Agreement term loan and revolving credit facility, the Company de-designated all of its interest rate swaps effective June 30, 2020. Accordingly, hedge accounting is not applicable, and subsequent changes to fair value of the interest rate swaps are recorded in Other (expense) income, net. The amounts previously recorded in Accumulated other comprehensive loss are amortized into Interest expense, net over the terms of the hedged forecasted interest payments. See Note 8 — Debt provides additional information regarding the Company’s interest rate swap contracts. (2) The Company has foreign exchange transaction risk because it typically enters into transactions in the normal course of business that are denominated in foreign currencies that differ from the local functional currency. The Company enters into short-term foreign currency forward exchange contracts to mitigate the cash flow risk associated with changes in foreign currency rates on forecasted foreign currency transactions. These contracts are accounted for at fair value with realized and unrealized gains and losses recognized in Other (expense) income, net because the Company does not designate these contracts as hedges for accounting purposes. All of the outstanding foreign currency forward exchange contracts at June 30, 2021 matured before July 31, 2021. (3) See Note 12 — Fair Value Disclosures for the determination of the fair values of these instruments.
Schedule of amounts recognized in statement of operations	The table below provides information regarding amounts recognized in the accompanying Condensed Consolidated Statements of Operations for derivative contracts for the periods indicated (in thousands). Three Months Ended Six Months Ended June 30, June 30, Amount recorded in: 2021 2020 2021 2020 Interest expense, net (1) $ 7,283 $ 7,322 $ 14,315 $ 10,514 Other expense (income), net (2) 1,494 9,715 (14,329) 22,314 Total (income) expense, net $ 8,777 $ 17,037 $ (14) $ 32,828 (1) Consists of interest expense from interest rate swap contracts.

Fair Value Disclosures (Tables)

Fair Value Disclosures (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities that are remeasured to fair value	The table below presents the fair values of certain financial assets and liabilities (in thousands). Description June 30, December 31, Assets: Values based on Level 1 inputs: Deferred compensation plan assets (1) $ 8,642 $ 2,589 Total Level 1 inputs 8,642 2,589 Values based on Level 2 inputs: Deferred compensation plan assets (1) 90,946 85,932 Foreign currency forward contracts (2) 44 885 Total Level 2 inputs 90,990 86,817 Total Assets $ 99,632 $ 89,406 Liabilities: Values based on Level 2 inputs: Deferred compensation plan liabilities (1) $ 106,390 $ 94,538 Foreign currency forward contracts (2) 182 2,399 Interest rate swap contracts (3) 80,041 109,175 Total Level 2 inputs 186,613 206,112 Total Liabilities $ 186,613 $ 206,112 (1) The Company has a deferred compensation plan for the benefit of certain highly compensated officers, managers and other key employees. The assets consist of investments in money market funds, mutual funds and company-owned life insurance contracts, which are valued based on Level 1 or Level 2 inputs. The related deferred compensation plan liabilities are recorded at fair value, or the estimated amount needed to settle the liability, which the Company considers to be a Level 2 input. (2) The Company enters into foreign currency forward exchange contracts to hedge the effects of adverse fluctuations in foreign currency exchange rates (see Note 11 — Derivatives and Hedging). Valuation of these contracts is based on observable foreign currency exchange rates in active markets, which the Company considers to be a Level 2 input. (3) The Company has interest rate swap contracts that hedge the risk of variability from interest payments on its borrowings (see Note 8 — Debt). The fair values of interest rate swaps are based on mark-to-market valuations prepared by a third-party broker. Those valuations are based on observable interest rates from recently executed market transactions and other observable market data, which the Company considers to be Level 2 inputs. The Company independently corroborates the reasonableness of the valuations prepared by the third-party broker by using an electronic quotation service.
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	The table below presents the carrying amounts (net of deferred financing costs) and fair values of financial instruments that are not recorded at fair value in the Company’s Condensed Consolidated Balance Sheets (in thousands). The estimated fair value of the financial instruments was derived from quoted market prices provided by an independent dealer, which the Company considers to be a Level 2 input. Carrying Amount Fair Value June 30, December 31, June 30, December 31, Description 2021 2020 2021 2020 2028 Notes $ 791,302 $ 790,783 $ 846,248 $ 846,296 2029 Notes 592,742 — 611,418 — 2030 Notes 791,087 790,690 819,608 843,800 Total $ 2,175,131 $ 1,581,473 $ 2,277,274 $ 1,690,096

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Lease costs	The table below presents the Company’s net lease cost and certain other information related to the Company’s leasing activities as of and for the periods indicated (dollars in thousands). Three Months Ended Six Months Ended June 30, June 30, Description: 2021 2020 2021 2020 Operating lease cost (1) $ 32,620 $ 35,173 $ 65,485 $ 73,134 Variable lease cost (2) 4,121 3,973 8,423 8,376 Sublease income (10,584) (10,719) (20,923) (21,810) Total lease cost, net (3) $ 26,157 $ 28,427 $ 52,985 $ 59,700 Cash paid for amounts included in the measurement of operating $ 35,324 $ 34,026 $ 70,251 $ 68,962 Cash receipts from sublease arrangements $ 10,364 $ 9,503 $ 20,459 $ 18,920 Right-of-use assets obtained in exchange for new operating lease $ 2,248 $ 3,616 $ 9,294 $ 18,535 (1) Included in operating lease cost was $10.7 million and $10.6 million for the three months ended June 30, 2021 and 2020, respectively, and $21.1 million and $21.2 million for the six months ended June 30, 2021 and 2020, respectively, for costs related to subleasing activities. (2) These amounts are primarily variable lease and nonlease costs that were not fixed at the lease commencement date or are dependent on something other than an index or a rate. (3) The Company did not capitalize any operating lease costs during any of the periods presented.
Supplemental balance sheet information	The table below indicates where the discounted operating lease payments from the above table are classified in the accompanying Condensed Consolidated Balance Sheets (in thousands). June 30, December 31, Description: 2021 2020 Accounts payable and accrued liabilities $ 86,381 $ 83,995 Operating leases - liabilities 745,108 780,166 Total operating lease liabilities per the Condensed Consolidated Balance Sheets $ 831,489 $ 864,161

Business and Basis of Present_3

Business and Basis of Presentation - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2021USD ($)	Jun. 30, 2021USD ($)countryenterprise	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)countryenterprisesegment	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of organizations Company serves | enterprise		14,000		14,000
Number of countries in which entity operates | country		100		100
Number of reportable segments | segment				3
Cash and cash equivalents, and restricted cash		$ 800,457	$ 356,633	$ 800,457	$ 356,633	$ 712,583	$ 280,836
Cash and cash equivalents		796,257		796,257		$ 712,583
Restricted cash		4,200		4,200
Proceeds from event cancellation insurance claims	$ 150,000
Gain on event cancellation insurance claims	$ 135,500	$ 135,545	$ 0	$ 135,545	$ 0

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - USD ($) $ in Thousands	Jun. 17, 2021	Jun. 30, 2021	Jun. 30, 2020
Business Acquisition [Line Items]
Cash paid for acquisition net of cash acquired		$ 22,774	$ 0
Pulse Q&A Inc.
Business Acquisition [Line Items]
Percent of outstanding membership interests acquired	100.00%
Purchase price	$ 30,000
Cash paid for acquisition net of cash acquired	22,800
Future compensation expense	$ 4,500
Future compensation expense, recognition period	3 years
Acquired finite lived intangible assets and goodwill	$ 30,600
Acquired other liabilities	$ 600

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Changes to Carrying Amount of Goodwill by Reporting Unit (Details) - USD ($)	3 Months Ended	6 Months Ended
	Sep. 30, 2020	Jun. 30, 2021
Goodwill [Line Items]
Goodwill impairment	$ 0
Goodwill [Roll Forward]
Beginning balance		$ 2,945,547,000
Additions due to an acquisition		11,172,000
Foreign currency translation impact		(1,253,000)
Ending balance		2,955,466,000
Goodwill, accumulated impairment losses		0
Research
Goodwill [Roll Forward]
Beginning balance		2,664,732,000
Additions due to an acquisition		11,172,000
Foreign currency translation impact		(1,398,000)
Ending balance		2,674,506,000
Conferences
Goodwill [Roll Forward]
Beginning balance		184,091,000
Additions due to an acquisition		0
Foreign currency translation impact		(20,000)
Ending balance		184,071,000
Consulting
Goodwill [Roll Forward]
Beginning balance		96,724,000
Additions due to an acquisition		0
Foreign currency translation impact		165,000
Ending balance		$ 96,889,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Carrying Amounts of Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance			$ 1,279,386
Additions due to an acquisition			19,460
Intangible assets fully amortized			82,384
Foreign currency translation impact			8,121
Gross cost, ending balance	$ 1,224,583		1,224,583
Accumulated amortization	(449,104)		(449,104)		$ (472,388)
Finite-lived intangible assets, net	775,479		775,479		806,998
Amortization of intangibles	26,154	$ 31,208	56,668	$ 63,387
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance			1,154,210
Additions due to an acquisition			7,980
Intangible assets fully amortized			17,788
Foreign currency translation impact			7,895
Gross cost, ending balance	1,152,297		1,152,297
Accumulated amortization	(414,460)		(414,460)		(381,776)
Finite-lived intangible assets, net	737,837		$ 737,837		772,434
Customer Relationships | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			6 years
Customer Relationships | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			13 years
Software
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance			$ 110,597
Additions due to an acquisition			11,200
Intangible assets fully amortized			60,631
Foreign currency translation impact			226
Gross cost, ending balance	61,392		61,392
Accumulated amortization	(30,394)		(30,394)		(83,320)
Finite-lived intangible assets, net	30,998		$ 30,998		27,277
Software | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			3 years
Software | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			7 years
Content
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance			$ 3,965
Additions due to an acquisition			0
Intangible assets fully amortized			3,965
Foreign currency translation impact			0
Gross cost, ending balance	0		0
Accumulated amortization	0		0		(3,595)
Finite-lived intangible assets, net	0		$ 0		370
Content | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			2 years
Content | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			3 years
Other
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance			$ 10,614
Additions due to an acquisition			280
Intangible assets fully amortized			0
Foreign currency translation impact			0
Gross cost, ending balance	10,894		10,894
Accumulated amortization	(4,250)		(4,250)		(3,697)
Finite-lived intangible assets, net	$ 6,644		$ 6,644		$ 6,917
Other | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			2 years
Other | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life			11 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Estimated Future Amortization Expense By Year From Amortizable Intangibles (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2021 (remaining six months)	$ 52,600
2022	101,768
2023	101,752
2024	94,540
2025	84,001
Thereafter	340,818
Finite-lived intangible assets, net	$ 775,479	$ 806,998

Revenue and Related Matters - D

Revenue and Related Matters - Disaggregation of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,167,319	$ 973,135	$ 2,271,357	$ 1,992,026
Research
Disaggregation of Revenue [Line Items]
Total revenues	1,003,238	875,329	1,982,970	1,784,620
Conferences
Disaggregation of Revenue [Line Items]
Total revenues	58,179	317	82,981	14,187
Consulting
Disaggregation of Revenue [Line Items]
Total revenues	105,902	97,489	205,406	193,219
United States and Canada
Disaggregation of Revenue [Line Items]
Total revenues	746,365	631,579	1,454,783	1,281,878
United States and Canada | Research
Disaggregation of Revenue [Line Items]
Total revenues	646,432	573,245	1,277,765	1,163,400
United States and Canada | Conferences
Disaggregation of Revenue [Line Items]
Total revenues	40,328	317	59,927	6,297
United States and Canada | Consulting
Disaggregation of Revenue [Line Items]
Total revenues	59,605	58,017	117,091	112,181
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	286,683	226,968	549,959	465,137
Europe, Middle East and Africa | Research
Disaggregation of Revenue [Line Items]
Total revenues	236,756	196,854	466,957	402,794
Europe, Middle East and Africa | Conferences
Disaggregation of Revenue [Line Items]
Total revenues	14,468	0	17,181	2,147
Europe, Middle East and Africa | Consulting
Disaggregation of Revenue [Line Items]
Total revenues	35,459	30,114	65,821	60,196
Other International
Disaggregation of Revenue [Line Items]
Total revenues	134,271	114,588	266,615	245,011
Other International | Research
Disaggregation of Revenue [Line Items]
Total revenues	120,050	105,230	238,248	218,426
Other International | Conferences
Disaggregation of Revenue [Line Items]
Total revenues	3,383	0	5,873	5,743
Other International | Consulting
Disaggregation of Revenue [Line Items]
Total revenues	$ 10,838	$ 9,358	$ 22,494	$ 20,842

Revenue and Related Matters - T

Revenue and Related Matters - Timing Of Revenue Recognition Liabilities per Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,167,319	$ 973,135	$ 2,271,357	$ 1,992,026
Transferred over time
Disaggregation of Revenue [Line Items]
Total revenues	1,002,743	879,194	1,981,172	1,789,814
Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	164,576	93,941	290,185	202,212
Research
Disaggregation of Revenue [Line Items]
Total revenues	1,003,238	875,329	1,982,970	1,784,620
Research | Transferred over time
Disaggregation of Revenue [Line Items]
Total revenues	916,754	810,564	1,810,841	1,639,776
Research | Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	86,484	64,765	172,129	144,844
Conferences
Disaggregation of Revenue [Line Items]
Total revenues	58,179	317	82,981	14,187
Conferences | Transferred over time
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Conferences | Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	58,179	317	82,981	14,187
Consulting
Disaggregation of Revenue [Line Items]
Total revenues	105,902	97,489	205,406	193,219
Consulting | Transferred over time
Disaggregation of Revenue [Line Items]
Total revenues	85,989	68,630	170,331	150,038
Consulting | Transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues	$ 19,913	$ 28,859	$ 35,075	$ 43,181

Revenue and Related Matters - R

Revenue and Related Matters - Revenue Remaining Performance Obligation (Details) $ in Millions	Jun. 30, 2021USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 3,700
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 1,229.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected timing of satisfaction	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 1,754.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation, amount	$ 676.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected timing of satisfaction

Revenue and Related Matters - S

Revenue and Related Matters - Schedule of Contract with Customer, Asset and Liability (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Assets:
Fees receivable, gross	$ 1,110,562		$ 1,110,562		$ 1,251,508
Contract assets recorded in Prepaid expenses and other current assets	22,637		22,637		14,440
Contract liabilities:
Deferred revenues (current liability)	2,152,043		2,152,043		1,974,548
Non-current deferred revenues recorded in Other liabilities	31,826		31,826		26,754
Total contract liabilities	2,183,869		2,183,869		$ 2,001,302
Revenue recognized previously attributable to deferred revenues	$ 817,300	$ 692,600	$ 1,261,900	$ 1,087,900

Computation of Earnings Per S_3

Computation of Earnings Per Share - Calculations Of Basic And Diluted (Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income used for calculating basic and diluted income per share	$ 271,236	$ 164,100	$ 55,077	$ 75,097	$ 435,336	$ 130,174
Denominator:
Weighted average number of common shares used in the calculation of basic income per share (in shares)	85,712		89,323		87,032	89,271
Dilutive effect of outstanding awards associated with stock-based compensation plans (in shares)	877		457		889	696
Shares used in the calculation of diluted income per share (in shares)	86,589		89,780		87,921	89,967
Basic income per share (in dollars per share)	$ 3.16		$ 0.62		$ 5	$ 1.46
Diluted income per share (in dollars per share)	$ 3.13		$ 0.61		$ 4.95	$ 1.45

Computation of Earnings Per S_4

Computation of Earnings Per Share - Additional information (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of (loss) income per share (in shares)	0.1	1.3	0.1	0.8

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - $ / shares shares in Millions	Jun. 30, 2021	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Number of shares available for grant (in shares)	4.2
Common stock par value (in dollars per share)	$ 0.0005	$ 0.0005

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-based Compensation Expense by Award Type and Expense Category (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Feb. 03, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	$ 26.2	$ 15.7	$ 62.3	$ 40.8
Cost of services and product development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	8	7.1	21.7	19.2
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	18.2	8.6	40.6	21.6
Stock appreciation rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	2	1.9	4	3.6
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	24	13.6	57.9	36.8
Common stock equivalents
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	0.2	0.2	0.4	0.4
Retirement eligible employees equity award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)	$ 11.3	$ 5.2	32.8	$ 16.8
Performance-based RSUs | Executive officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense (credit)			$ 6.5
Target performance percentage	50.00%		50.00%		95.00%

Segment Information - Informati

Segment Information - Information About Reportable Segments (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)segment	Jun. 30, 2020USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			3
Operating income	$ 274,714,000	$ 99,651,000	$ 500,126,000	$ 224,370,000
Intersegment revenues
Segment Reporting Information [Line Items]
Revenues			0
Reportable segments
Segment Reporting Information [Line Items]
Revenues	1,167,319,000	973,135,000	2,271,357,000	1,992,026,000
Operating income	827,503,000	654,936,000	1,604,869,000	1,331,729,000
Corporate and other expenses
Segment Reporting Information [Line Items]
Operating income	(552,789,000)	(555,285,000)	(1,104,743,000)	(1,107,359,000)
Research | Reportable segments
Segment Reporting Information [Line Items]
Revenues	1,003,238,000	875,329,000	1,982,970,000	1,784,620,000
Operating income	742,131,000	632,624,000	1,466,503,000	1,286,094,000
Conferences | Reportable segments
Segment Reporting Information [Line Items]
Revenues	58,179,000	317,000	82,981,000	14,187,000
Operating income	42,602,000	(11,230,000)	56,498,000	(17,290,000)
Consulting | Reportable segments
Segment Reporting Information [Line Items]
Revenues	105,902,000	97,489,000	205,406,000	193,219,000
Operating income	$ 42,770,000	$ 33,542,000	$ 81,868,000	$ 62,925,000

Segment Information - Reconcili

Segment Information - Reconciliation of Segment Gross Contribution to Net Income (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended				6 Months Ended
	May 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Costs and expenses:
Cost of services and product development		$ 350,802		$ 322,551		$ 685,269	$ 663,829
Selling, general and administrative		488,496		494,840		975,751	991,479
Acquisition and integration charges		1,302		2,157		1,942	3,716
Operating income		274,714		99,651		500,126	224,370
Interest expense and other, net		(31,072)		(40,695)		(41,731)	(68,559)
Gain on event cancellation insurance claims	$ 135,500	135,545		0		135,545	0
Less: Provision for income taxes		107,951		3,879		158,604	25,637
Net income		271,236	$ 164,100	55,077	$ 75,097	435,336	130,174
Reportable segments
Costs and expenses:
Operating income		827,503		654,936		$ 1,604,869	1,331,729
Reportable segments | Maximum
Costs and expenses:
Percent of target bonus allocated to segments						100.00%
Corporate and other expenses
Costs and expenses:
Cost of services and product development		10,986		4,352		$ 18,781	3,532
Selling, general and administrative		488,496		494,840		975,751	991,479
Depreciation and amortization		52,005		53,936		108,269	108,632
Acquisition and integration charges		1,302		2,157		1,942	3,716
Operating income		$ (552,789)		$ (555,285)		$ (1,104,743)	$ (1,107,359)

Debt - Borrowings (Details)

Debt - Borrowings (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal amount outstanding	$ 2,495,790	$ 2,006,046
Less: deferred financing fees	(32,614)	(27,245)
Net balance sheet carrying amount	2,463,176	1,978,801
Term Loan Facility | 2020 Credit Agreement
Debt Instrument [Line Items]
Principal amount outstanding	290,000	395,000
Line of Credit | Revolving credit facility | 2020 Credit Agreement
Debt Instrument [Line Items]
Principal amount outstanding	0	5,000
Senior Notes | 2028 Notes
Debt Instrument [Line Items]
Principal amount outstanding	800,000	800,000
Senior Notes | 2029 Notes
Debt Instrument [Line Items]
Principal amount outstanding	600,000	0
Senior Notes | 2030 Notes
Debt Instrument [Line Items]
Principal amount outstanding	800,000	800,000
Other
Debt Instrument [Line Items]
Principal amount outstanding	$ 5,790	$ 6,046

Debt - Footnote to Borrowings (

Debt - Footnote to Borrowings (Details)	Sep. 28, 2020USD ($)	Jun. 30, 2021USD ($)segment	Jun. 30, 2020	Jun. 30, 2021USD ($)segment	Jun. 18, 2021USD ($)	Jun. 22, 2020USD ($)
Debt Instrument [Line Items]
Weighted average annual effect rate		4.96%	4.99%	4.96%
Term Loan Facility | 2020 Credit Agreement
Debt Instrument [Line Items]
Contractual annualized interest rate		1.50%		1.50%
Floating eurodollar base rate		0.125%		0.125%
Additional interest above base rate				1.375%
Aggregate principal amount	$ 400,000,000
Debt term	5 years
Senior Notes | 2028 Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 800,000,000		$ 800,000,000		$ 800,000,000
Debt instrument, fixed interest rate						4.50%
Senior Notes | 2029 Notes
Debt Instrument [Line Items]
Aggregate principal amount		600,000,000		600,000,000	$ 600,000,000
Debt instrument, fixed interest rate					3.625%
Senior Notes | 2030 Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 800,000,000	$ 800,000,000		$ 800,000,000
Debt instrument, fixed interest rate	3.75%
Connecticut Economic Development Program
Debt Instrument [Line Items]
Number of loans | segment		2		2
Connecticut Economic Development Program | Economic Development Loan 1
Debt Instrument [Line Items]
Debt instrument, fixed interest rate		3.00%		3.00%
Debt term				10 years
Connecticut Economic Development Program | Economic Development Loan 2
Debt Instrument [Line Items]
Debt instrument, fixed interest rate		1.75%		1.75%
Debt term				10 years
Revolving credit facility | Line of Credit | 2020 Credit Agreement
Debt Instrument [Line Items]
Remaining borrowing capacity		$ 1,000,000,000		$ 1,000,000,000
Debt term	5 years

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	Jun. 18, 2021	Sep. 28, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 22, 2020
Debt Instrument [Line Items]
Proceeds from borrowings			$ 600,000,000	$ 800,000,000
Repayments of long-term debt			105,256,000	$ 853,094,000
2029 Notes | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 600,000,000		600,000,000
Debt instrument, fixed interest rate	3.625%
Debt instrument, issue price, percent	100.00%
2029 Notes | Senior Notes | Debt Instrument Redemption Option One
Debt Instrument [Line Items]
Percentage of principal amount redeemed	40.00%
Redemption price percentage	103.625%
2029 Notes | Senior Notes | Debt Instrument Redemption Option Two
Debt Instrument [Line Items]
Redemption price percentage	100.00%
2029 Notes | Senior Notes | Debt Instrument Redemption Option Three
Debt Instrument [Line Items]
Redemption price percentage	101.00%
2030 Notes | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount		$ 800,000,000	$ 800,000,000
Debt instrument, fixed interest rate		3.75%
Debt instrument, issue price, percent		100.00%
Percentage of principal amount redeemed			40.00%
2028 Notes | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount			$ 800,000,000		$ 800,000,000
Debt instrument, fixed interest rate					4.50%
Debt instrument, issue price, percent					100.00%
Percentage of principal amount redeemed			40.00%
2020 Credit Agreement | Variable Rate Component, One | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
2020 Credit Agreement | Variable Rate Component, One | Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.125%
2020 Credit Agreement | Variable Rate Component, One | Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		1.25%
2020 Credit Agreement | Variable Rate Component, One | Federal Reserve Board of New York Rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
2020 Credit Agreement | Variable Rate Component, Two | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		1.125%
2020 Credit Agreement | Variable Rate Component, Two | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
2020 Credit Agreement | Term Loan Facility
Debt Instrument [Line Items]
Aggregate principal amount		$ 400,000,000
Debt term		5 years
Proceeds from borrowings		$ 400,000,000
Repayments of long-term debt		$ 100,000,000
2020 Credit Agreement | Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Debt term		5 years
Line of credit facility, maximum borrowing capacity		$ 1,000,000,000
Accordion feature, increase limit		$ 1,000,000,000
2020 Credit Agreement | Revolving credit facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Unused borrowing capacity, fee percent		0.175%
2020 Credit Agreement | Revolving credit facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Unused borrowing capacity, fee percent		0.40%
2020 Credit Agreement | Letter of Credit | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 75,000,000

Debt - Interest Rate Swaps (Det

Debt - Interest Rate Swaps (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)derivative_instrumentoutstanding_contract	Dec. 31, 2020USD ($)outstanding_contract
Derivative [Line Items]
Number of contracts | outstanding_contract	30	167
Interest rate swap contracts total notional value	$ 1,622,893	$ 1,830,063
Interest rate swaps
Derivative [Line Items]
Number of contracts | derivative_instrument	4
Interest rate swap contracts total notional value	$ 1,400,000
Term of contract	30 days
Loss on release of interest rate swap recognized in AOCI	$ 89,700
Net negative fair value (liability)	(80,000)	(109,200)
Interest rate swaps | Accumulated Other Comprehensive Loss, Net
Derivative [Line Items]
Net negative fair value (liability)	$ (67,400)	$ (78,100)
Interest rate swaps | Minimum
Derivative [Line Items]
Fixed interest rate	2.13%
Interest rate swaps | Maximum
Derivative [Line Items]
Fixed interest rate	3.04%

Equity - Share Repurchase Progr

Equity - Share Repurchase Program and Share Repurchase Activity (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jul. 29, 2021	Apr. 30, 2021	Feb. 28, 2021	Dec. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount		$ 2,000,000,000		$ 2,000,000,000					$ 1,200,000,000
Stock repurchase program, additional authorized amount							$ 500,000,000	$ 300,000,000
Stock repurchase program, remaining authorized repurchase amount		$ 300,000,000		$ 300,000,000
Number of shares repurchased (in shares)		3,094,706	5,999	5,369,416	423,706
Cash paid for repurchased shares		$ 684,900,000	$ 698,000	$ 1,083,350,000	$ 73,862,000
Treasury stock, average price paid per share (in dollars per share)		$ 218.33	$ 116.29	$ 202.28	$ 150.72
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, additional authorized amount						$ 800,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 231,000,000
Open Market Purchases
Equity, Class of Treasury Stock [Line Items]
Cash paid for repurchased shares				$ 8,000,000	$ 10,000,000
Open Market Purchases | Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Cash paid for repurchased shares	$ 10,800,000

Equity - Changes in AOCI_L by C

Equity - Changes in AOCI/L by Component (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 891,594	$ 1,090,428	$ 890,275	$ 938,593	$ 1,090,428	$ 938,593
Change in AOCL before reclassifications to income	4,639		13,882		5,316	(79,553)
Reclassifications from AOCL/I to income	5,561		12,915		10,934	15,316
Other comprehensive income (loss), net of tax	10,200	6,050	26,797	(91,034)	16,250	(64,237)
Ending balance	527,638	891,594	991,219	890,275	527,638	991,219
Derivative reclassifications	(8,777)		(17,037)		14	(32,828)
Interest (income) expense, net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Derivative reclassifications	(7,283)		(7,322)		(14,315)	(10,514)
Interest rate swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Loss to be reclassified within twelve months					27,100
Interest rate swaps | Interest (income) expense, net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Derivative reclassifications	7,300		7,300		14,300	10,500
Interest rate swaps | Other Expense
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Loss on release of interest rate swap recognized in earnings			10,300			10,300
Interest Rate Swaps
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(72,834)	(78,104)	(91,896)	(47,164)	(78,104)	(47,164)
Change in AOCL before reclassifications to income	0		(9,935)		0	(56,989)
Reclassifications from AOCL/I to income	5,457		12,835		10,727	15,157
Other comprehensive income (loss), net of tax	5,457		2,900		10,727	(41,832)
Ending balance	(67,377)	(72,834)	(88,996)	(91,896)	(67,377)	(88,996)
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(9,206)	(9,309)	(8,505)	(8,584)	(9,309)	(8,584)
Change in AOCL before reclassifications to income	0		0		0	0
Reclassifications from AOCL/I to income	104		80		207	159
Other comprehensive income (loss), net of tax	104		80		207	159
Ending balance	(9,102)	(9,206)	(8,425)	(8,505)	(9,102)	(8,425)
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(11,138)	(11,815)	(68,571)	(22,190)	(11,815)	(22,190)
Change in AOCL before reclassifications to income	4,639		23,817		5,316	(22,564)
Reclassifications from AOCL/I to income	0		0		0	0
Other comprehensive income (loss), net of tax	4,639		23,817		5,316	(22,564)
Ending balance	(6,499)	(11,138)	(44,754)	(68,571)	(6,499)	(44,754)
Accumulated Other Comprehensive Loss, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(93,178)	(99,228)	(168,972)	(77,938)	(99,228)	(77,938)
Other comprehensive income (loss), net of tax	10,200	6,050	26,797	(91,034)
Ending balance	$ (82,978)	$ (93,178)	$ (142,175)	$ (168,972)	$ (82,978)	$ (142,175)

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 107,951	$ 3,879	$ 158,604	$ 25,637
Effective income tax rate	28.50%	6.60%	26.70%	16.50%
Tax benefit from intercompany sale of intellectual property		$ 28,300		$ 28,300
Unrecognized tax benefits	$ 130,100		$ 130,100		$ 127,100
Decrease in unrecognized tax benefits is reasonably possible	$ 9,200		$ 9,200

Derivatives and Hedging - Outst

Derivatives and Hedging - Outstanding Derivatives Contracts (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)derivative_instrumentoutstanding_contract	Dec. 31, 2020USD ($)outstanding_contract
Derivatives, Fair Value [Line Items]
Number of Contracts | outstanding_contract	30	167
Notional Amounts	$ 1,622,893	$ 1,830,063
Fair Value Asset (Liability), Net	(80,179)	(110,689)
Unrealized Loss Recorded in AOCL, net of tax	$ (67,377)	$ (78,104)
Interest rate swaps
Derivatives, Fair Value [Line Items]
Number of Contracts | derivative_instrument	4
Notional Amounts	$ 1,400,000
Not Designated as Hedging Instrument | Other liabilities | Interest rate swaps
Derivatives, Fair Value [Line Items]
Number of Contracts | outstanding_contract	4	4
Notional Amounts	$ 1,400,000	$ 1,400,000
Fair Value Asset (Liability), Net	(48,700)	(74,289)
Unrealized Loss Recorded in AOCL, net of tax	(67,377)	(78,104)
Not Designated as Hedging Instrument | Accrued liabilities | Interest rate swaps
Derivatives, Fair Value [Line Items]
Fair Value Asset (Liability), Net	$ (31,341)	$ (34,886)
Not Designated as Hedging Instrument | Accrued liabilities | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Number of Contracts | outstanding_contract	26	163
Notional Amounts	$ 222,893	$ 430,063
Fair Value Asset (Liability), Net	(138)	(1,514)
Unrealized Loss Recorded in AOCL, net of tax	$ 0	$ 0

Derivatives and Hedging - Amoun

Derivatives and Hedging - Amounts Recognized in the Condensed Consolidated Statements of Operations for Derivative Contracts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	$ 8,777	$ 17,037	$ (14)	$ 32,828
Interest (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	7,283	7,322	14,315	10,514
Interest (income) expense, net | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	(7,300)	(7,300)	(14,300)	(10,500)
Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Total (income) expense, net	$ 1,494	9,715	$ (14,329)	22,314
Other Expense | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Loss on release of interest rate swap recognized in earnings		$ 10,300		$ 10,300

Fair Value Disclosures - Assets

Fair Value Disclosures - Assets And Liabilities Measured At Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets:
Assets measured at fair value on a recurring basis	$ 99,632	$ 89,406
Liabilities:
Liabilities measured at fair value on a recurring basis	186,613	206,112
Fair Value, Inputs, Level 1
Assets:
Assets measured at fair value on a recurring basis	8,642	2,589
Fair Value, Inputs, Level 2
Assets:
Assets measured at fair value on a recurring basis	90,990	86,817
Liabilities:
Liabilities measured at fair value on a recurring basis	186,613	206,112
Fair Value, Inputs, Level 2 | Foreign currency forward contracts
Assets:
Assets measured at fair value on a recurring basis	44	885
Liabilities:
Liabilities measured at fair value on a recurring basis	182	2,399
Fair Value, Inputs, Level 2 | Interest rate swap contracts
Liabilities:
Liabilities measured at fair value on a recurring basis	80,041	109,175
Fair Value, Inputs, Level 2 | Deferred compensation plan assets
Assets:
Assets measured at fair value on a recurring basis	90,946	85,932
Fair Value, Inputs, Level 2 | Deferred compensation plan liabilities
Liabilities:
Liabilities measured at fair value on a recurring basis	$ 106,390	$ 94,538

Fair Value Disclosures - Fair V

Fair Value Disclosures - Fair Value of Debt Instruments (Details) - Senior Notes - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	$ 2,175,131	$ 1,581,473
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,277,274	1,690,096
2028 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	791,302	790,783
2028 Notes | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	846,248	846,296
2029 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	592,742	0
2029 Notes | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	611,418	0
2030 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Amount	791,087	790,690
2030 Notes | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 819,608	$ 843,800

Leases - Narrative (Details)

Leases - Narrative (Details)	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Renewal term	5 years
Option to terminate, term	1 year

Leases - Net Lease Costs (Detai

Leases - Net Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Operating lease cost	$ 32,620	$ 35,173	$ 65,485	$ 73,134
Variable lease cost	4,121	3,973	8,423	8,376
Sublease income	(10,584)	(10,719)	(20,923)	(21,810)
Total lease cost, net	26,157	28,427	52,985	59,700
Cash paid for amounts included in the measurement of operating lease liabilities	35,324	34,026	70,251	68,962
Cash receipts from sublease arrangements	10,364	9,503	20,459	18,920
Right-of-use assets obtained in exchange for new operating lease liabilities	2,248	3,616	9,294	18,535
Cost for subleasing activities	$ 10,700	$ 10,600	$ 21,100	$ 21,200

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Accounts payable and accrued liabilities	$ 86,381	$ 83,995
Operating leases - liabilities	745,108	780,166
Total operating lease liabilities per the Condensed Consolidated Balance Sheets	$ 831,489	$ 864,161
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accounts payable and accrued liabilities	Accounts payable and accrued liabilities

Subsequent Events - (Details)

Subsequent Events - (Details) - USD ($)	Jul. 31, 2021	Jul. 29, 2021	Jun. 30, 2021	Apr. 30, 2021	Feb. 28, 2021	Dec. 31, 2015
Subsequent Event [Line Items]
Stock repurchase program, additional authorized amount				$ 500,000,000	$ 300,000,000
Stock repurchase program, authorized amount			$ 2,000,000,000			$ 1,200,000,000
Stock repurchase program, remaining authorized repurchase amount			$ 300,000,000
Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program, additional authorized amount		$ 800,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 231,000,000