Commitments and Contingencies - Additional Information (Detail) Claim in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) Claim	Dec. 31, 2016 USD ($) Claim	Dec. 31, 2015 USD ($) Claim	Dec. 31, 2014 Claim
Other Commitments [Line Items]
Asbestos-related liability and asset measurement period	10 years
Asbestos Related Matters [Member]
Other Commitments [Line Items]
Outstanding Active Pending Asbestos Claims | Claim	26	30	37	62
Percentage of asbestos liability related to pending claims	23.00%
Percentage of Estimated Receivable from Insurers with A- or Better Credit Rating	77.00%
Percentage of Asbestos Asset Related to Coverage in Place Agreements	42.00%
Benefit from Settlement Agreement with Asbestos Insurers		$ 2.1	$ (8.9)
Change in Defense Cost Estimate for Asbestos Matters	$ 0.0	4.9
Continuing Operations [Member] | Asbestos Related Matters [Member]
Other Commitments [Line Items]
Change in Defense Cost Estimate for Asbestos Matters	$ 0.0	$ (4.9)	$ (100.7)