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.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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