Litigation - Schedule of Loss Contingencies by Contingency (Detail) - Asbestos Claims [Member]	3 Months Ended
	Mar. 31, 2017 USD ($) Claim	Mar. 31, 2016 USD ($) Claim
Loss Contingencies [Line Items]
Total claims pending at the beginning of the period	6,618	6,212
New claims served	336	397
Claims dismissed	(80)	(90)
Claims settled	(88)	(80)
Total claims pending at the end of the period	6,786	6,439
Gross settlement and defense costs | $	$ 4,888,000	$ 4,027,000
Avg. gross settlement and defense costs per claim resolved | $	$ 29,100	$ 23,690