Summary of Allocation of Share Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 11,033	$ 8,887	$ 7,928
Tax benefit	3,362	2,746	2,643
Share-based compensation expense, net of tax	7,671	6,141	5,285
Cost of Sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	1,317	809	690
Engineering, Research and Development Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	1,000	705	502
Selling, General And Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 8,716	$ 7,373	$ 6,736