Segment Information - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($) segment
Segment Reporting Information [Line Items]
Number of operating segments (segment) | segment	2
2018 Restructuring Program | MIS
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 61.3
2018 Restructuring Program | MA
Segment Reporting Information [Line Items]
Cumulative expense incurred to date	$ 45.7