Other Intangible Assets, net and Goodwill - Other Intangible Assets, net (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	$ 2,855,468	$ 2,323,087
Finite-lived intangible assets, Accumulated Amortization	(758,385)	(658,875)
Total finite-lived intangible assets	2,097,083	1,664,212
Intangible assets, Gross	3,019,934	2,487,515
Total intangible assets	2,261,549	1,828,640
Trade names
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross	164,466	164,428
Customer relationships
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	657,935	280,493
Finite-lived intangible assets, Accumulated Amortization	(190,765)	(180,571)
Total finite-lived intangible assets	467,170	99,922
Databases and content
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	1,811,209	1,755,323
Finite-lived intangible assets, Accumulated Amortization	(399,675)	(342,385)
Total finite-lived intangible assets	1,411,534	1,412,938
Computer software
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	346,122	285,701
Finite-lived intangible assets, Accumulated Amortization	(164,996)	(135,919)
Total finite-lived intangible assets	181,126	149,782
Trade names
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	6,770	1,570
Finite-lived intangible assets, Accumulated Amortization	(492)	0
Total finite-lived intangible assets	6,278	$ 1,570
Backlog
Goodwill And Intangible Assets [Line Items]
Finite-lived intangible assets, Gross	33,432
Finite-lived intangible assets, Accumulated Amortization	(2,457)
Total finite-lived intangible assets	$ 30,975