Litigation - Summary of Activity in Asbestos Insurance Recoveries (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Loss Contingencies [Line Items]
Insurance receivable – asbestos, beginning of the year	$ 152,508
Insurance receivable – asbestos, end of the period	144,934
Asbestos Claims [Member]
Loss Contingencies [Line Items]
Insurance receivable – asbestos, beginning of the year	152,508	$ 100,342
Settlement and defense costs paid by insurance carriers	(7,574)	(9,050)
Insurance receivable – asbestos, end of the period	$ 144,934	$ 91,292