Litigation - Schedule of Loss Contingencies by Contingency (Detail) - Asbestos Claims [Member]	9 Months Ended
	Sep. 30, 2020 USD ($) Claim	Sep. 30, 2019 USD ($) Claim
Loss Contingencies [Line Items]
Total claims pending at the beginning of the period	6,102	6,772
New claims served	769	1,014
Claims dismissed	(725)	(803)
Claims settled	(278)	(282)
Total claims pending at the end of the period	5,868	6,701
Gross settlement and defense costs paid in period | $	$ 21,699,000	$ 14,969,000
Avg. gross settlement and defense costs per claim resolved | $	$ 21,630	$ 13,800