Share-Based Employee Compensation - Share-Based Compensation Related to Employees and Directors (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cost of employee share-based compensation included in income (loss), before income tax	$ 12,615	$ 9,285	$ 11,220
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cost of employee share-based compensation included in income (loss), before income tax	907	704	754
Operating expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cost of employee share-based compensation included in income (loss), before income tax	$ 11,708	$ 8,581	$ 10,466