Litigation - Schedule of Loss Contingencies by Contingency (Detail) - Asbestos Claims [Member]	3 Months Ended
	Mar. 31, 2019 USD ($) Claim	Mar. 31, 2018 USD ($) Claim
Loss Contingencies [Line Items]
Total claims pending at the beginning of the period	6,772	6,907
New claims served	333	287
Claims dismissed	(90)	(112)
Claims settled	(56)	(78)
Total claims pending at the end of the period	6,959	7,004
Gross settlement and defense costs | $	$ 2,789,000	$ 6,881,000
Avg. gross settlement and defense costs per claim resolved | $	$ 19,100	$ 36,220