Commitments and Contingencies - Roll forward of Asbestos Liability and Related Assets (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019
Changes in estimate during the period:
Asbestos-related liability		$ 91.4		$ 86.0
Asbestos-related assets(a)		91.0	[1]	67.2
Noncurrent portion		840.6		731.6
Noncurrent Asbestos Related Assets		353.7		319.6
Asbestos Related Matters [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Net Balance, Beginning		430.8		472.6
Changes in estimate during the period:
Asbestos provision(a)	[2]	(30.8)		(47.9)
Asbestos remeasurement		135.9	[3]	(68.1)
Settlement Agreement		(100.4)
Net cash activity and other(a)	[2]	(9.8)		(21.6)
Balance, Ending				430.8
Net Balance, Ending		487.3		430.8
Asbestos Related Matters [Member] | Liability [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Balance, Beginning		817.6		849.3
Changes in estimate during the period:
Asbestos provision(a)	[2]	(37.1)		(59.4)
Asbestos remeasurement		155.7	[3]	(4.5)
Settlement Agreement		0.0
Net cash activity and other(a)	[2]	(78.4)		(86.6)
Balance, Ending		932.0		817.6
Noncurrent portion				731.6
Asbestos Related Matters [Member] | Asset [Member]
Liability for Asbestos and Environmental Claims, Net [Roll Forward]
Balance, Beginning		386.8		376.7
Changes in estimate during the period:
Asbestos provision(a)		6.3		11.5
Asbestos remeasurement		(19.8)		(63.6)
Settlement Agreement		(100.4)		0.0
Net cash activity and other(a)		68.6		65.0
Balance, Ending		$ 444.7		$ 386.8

[1] The increase in asbestos-related assets as of December 31, 2020 primarily relates to a 2020 settlement agreement with an insurer accelerating payments previously included in a buyout agreement. Refer to Note 20, Commitments and Contingencies, for further information.

[2] 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.

[3] 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.