Litigation - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Reserves for total costs for asbestos liability claims pending or projected	$ 171,181	$ 142,869
Percentage attributable to settlement costs for unasserted claims projected to be filed	70.00%
Insurance recoveries receivable	$ 115,945	$ 95,388