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Acquisitions and Divestiture (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Feb. 28, 2023
Business Acquisition [Line Items]
Proceeds from sale of divested operation					$ 156,057	$ 0
Gain from sale of divested operation			$ 0	$ 0	135,410	$ 0
TalentNeuron
Business Acquisition [Line Items]
Gain from sale of divested operation					135,400
TalentNeuron
Business Acquisition [Line Items]
Sale of business, consideration							$ 161,100
Proceeds from sale of divested operation					156,100
Goodwill	$ 16,000		16,000		16,000
Intangible assets, net	9,500		9,500		9,500
Property, equipment and leasehold improvements, net,	4,500		4,500		4,500
Accounts receivable	11,800		11,800		11,800
Deferred revenues	$ 24,400		$ 24,400		$ 24,400
Gartner Research Products
Business Acquisition [Line Items]
Percent of outstanding membership interests acquired	100.00%		100.00%		100.00%
Purchase price	$ 7,900
UpCity, Inc.
Business Acquisition [Line Items]
Percent of outstanding membership interests acquired		100.00%
Purchase price		$ 6,400