Commitments and Contingencies - Summary of Net Asbestos Charges (Detail) - Asbestos Related Matters [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Asbestos Related Contingencies [Line Items]
Asbestos provision, net(a)	[1]	$ 30.8		$ 47.9
Asbestos remeasurement, net(b)		135.9	[2]	(68.1)
Settlement agreements and other		100.4
Continuing Operations [Member]
Asbestos Related Contingencies [Line Items]
Asbestos provision, net(a)	[1]	30.8		47.9	$ 53.8
Asbestos remeasurement, net(b)		135.9	[2]	(68.1)	10.0
Settlement agreements and other		(100.4)			(58.9)
Asbestos-related costs (benefit), net		$ 66.3		$ (20.2)	$ 4.9

[1] Includes certain administrative costs such as legal-related costs for insurance asset recoveries. The asbestos provision includes amounts to maintain a rolling 10-year provision prior to the transition in the third quarter of 2020 to full horizon.

[2] In the third quarter of 2020, we extended our projection to include pending claims and claims expected to be filed through 2052, reflecting the full time period over which we expect asbestos-related claims to be filed against us.