Commitments and Contingencies - Summary of Reconciliation of Company's Warranty Reserve that Represents Amounts Accrued for Surface Flaking Claims (Detail) - Surface Flaking Warranty Reserve [Member] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Product Warranty Liability [Line Items]
Beginning balance	$ 33,847	$ 29,673
Changes in estimates related to pre-existing warranties	0	0
Settlements made during the period	(2,683)	(2,611)
Ending balance	$ 31,164	$ 27,062