Commitments and Contingencies - Roll forward of Asbestos Liability and Related Assets (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Changes in estimate during the period:
Asbestos-related liability		$ 74.2	$ 77.1
Asbestos-related current assets		67.1	64.7
Noncurrent portion		775.1	800.1
Noncurrent Asbestos Related Assets		309.6	304.0
Asbestos Related Matters [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Net Balance, Beginning		508.5	573.7
Changes in estimate during the period:
Continuing operations	[1]	(53.8)	(56.5)
Asbestos remeasurement		10.0	(76.4)
Settlement Agreement		(58.9)
Net cash activity	[1]	(40.8)	(45.3)
Balance, Ending			508.5
Estimated asbestos exposure, net of expected recoveries from insurers and other responsible parties		472.6	508.5
Asbestos Related Matters [Member] | Liability [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Balance, Beginning		877.2	954.3
Changes in estimate during the period:
Continuing operations	[1]	(66.1)	(67.1)
Asbestos remeasurement		(5.8)	(66.4)
Settlement Agreement		0.0
Net cash activity	[1]	(88.2)	(77.8)
Balance, Ending		849.3	877.2
Noncurrent portion			800.1
Asbestos Related Matters [Member] | Asset [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Balance, Beginning		368.7	380.6
Changes in estimate during the period:
Continuing operations		12.3	10.6
Asbestos remeasurement		15.8	(10.0)
Settlement Agreement		(58.9)	0.0
Net cash activity		47.4	32.5
Balance, Ending		$ 376.7	$ 368.7

[1] (a)Includes certain administrative costs such as legal-related costs for insurance asset recoveries.