Goodwill and Intangible Assets - Schedule of Other Intangible Asset (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 534.6	$ 531.1
Accumulated Amortization	(350.3)	(343.6)
Net	184.3	187.5
Trade Name [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	173.7	173.5
Accumulated Amortization	(1.9)	(1.9)
Net	171.8	171.6
Customer Lists and Relationships [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	206.8	205.4
Accumulated Amortization	(195.7)	(190.2)
Net	$ 11.1	$ 15.2
Customer Lists and Relationships [Member] | Minimum [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Estimated Life Range (Years)	5 years	5 years
Customer Lists and Relationships [Member] | Maximum [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Estimated Life Range (Years)	15 years	15 years
Technology [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 154.1	$ 152.2
Accumulated Amortization	(152.7)	(151.5)
Net	$ 1.4	$ 0.7
Technology [Member] | Minimum [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Estimated Life Range (Years)	3 years	3 years
Technology [Member] | Maximum [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Estimated Life Range (Years)	4 years	4 years