Product Warranty Accrual Included in Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Other Accrued Liabilities [Line Items]
Balance as of January 1	$ 15,462	$ 14,719
Provision for warranties issued in current year	3,503	2,991
Recovery of pre-existing warranties	(289)	(121)
Payments	(2,577)	(2,599)
Balance as of June 30	$ 16,099	$ 14,990