Accrued Warranty Costs - Changes in Product Warranty Obligation (Accrued Warranty Costs) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Disclosure Accrued Product Warranty Costs [Abstract]
Balance at beginning of period	$ 10,551	$ 8,817
Amounts charged to SG&A	2,405	2,099
Costs incurred	(2,190)	(1,882)
Balance at end of period	$ 10,766	$ 9,034