Segment Information - Additional Information (Detail) $ in Millions		3 Months Ended				6 Months Ended
	Jan. 01, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)		Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Revenue		$ 667.4		$ 666.2		$ 1,375.8	$ 1,330.7
Number of business segments | segment						2
Operating profit (loss)		54.0		(3.5)	[1]	$ 155.8	18.3
Other Technology | Segment Reconciling Items
Segment Reporting Information [Line Items]
Operating profit (loss)		2.2		0.9		2.2	1.0
Technology
Segment Reporting Information [Line Items]
Revenue		80.7		91.4		220.6	170.6
Operating profit (loss)		$ 38.2		$ 34.4		120.2	$ 47.4
Technology | Software License Extensions and Renewals
Segment Reporting Information [Line Items]
Revenue	$ 53.0		$ 53.0			$ 53.0

[1] Amounts were changed to conform to the current-year presentation. See Note 3.