Purchase Price Allocation (Parenthetical) (Detail) - Bureau van Dijk (BvD) [Member]	Aug. 10, 2017
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	21 years
Trade Names [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	18 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	23 years
Databases [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	10 years
Product Technology [Member]
Business Acquisition [Line Items]
Weighted average life of intangible assets acquired (in years)	12 years