Stock-Based Compensation Impact on Company Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted stock-based compensation expense	$ 1,690	$ 1,606	$ 5,104	$ 4,619
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted stock-based compensation expense	586	573	1,830	1,505
Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Restricted stock-based compensation expense	$ 1,104	$ 1,033	$ 3,274	$ 3,114