Litigation - Schedule of Loss Contingencies by Contingency (Detail) - Asbestos Claims [Member]	3 Months Ended
	Mar. 31, 2021 USD ($) Claim	Mar. 31, 2020 USD ($) Claim
Loss Contingencies [Line Items]
Total claims pending at the beginning of the period	5,891	6,102
New claims served	318	273
Claims dismissed	(141)	(86)
Claims settled	(104)	(108)
Total claims pending at the end of period	5,964	6,181
Administrative closures	(2,887)
Total active claims at the end of the period	3,077
Gross settlement and defense costs paid in period | $	$ 3,340,000	$ 6,206,000
Avg. gross settlement and defense costs per claim resolved | $	$ 13,630	$ 31,990