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Leases - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
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Dec. 31, 2020 | Sep. 30, 2020
Office Space [Member] | Scenario, Forecast [Member] |  |
Lessee Lease Description [Line Items] |  |
Variable incentive payment received | $ 3.5 |
Topic 842 [Member] | SiriusDecisions, Inc [Member] | Facility Lease [Member] |  |
Lessee Lease Description [Line Items] |  |
Operating lease right-of-use asset impairments |  | $ 1.4

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- Definition Amount of loss from impairment of right-of-use asset from operating lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 25 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121593497&loc=SL77918431-209957 + Details
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- Definition Amount of variable lease payments from operating, direct financing, and sales-type leases, excluding amount included in measurement of lease receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 30 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919372-209981 + Details
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- Details
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