Stock-Based Compensation - Additional Information (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 [Line Items]
Stock compensation expense	$ 700	$ 700	$ 1,400	$ 2,600
Expense reversal of performance units			500
Restricted Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	500	500	1,400	1,600
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	57	200	400	800
Employee Stock Purchase Plan ("ESPP") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	55	$ 54	$ 200	$ 137
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	$ 33