Restructuring and Severance (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Restructuring And Related Activities [Abstract]
Restructuring and Severance Beginning Balance			$ 1,377	$ 1,149
Restructuring expense incurred for the period	$ 215	$ 1,825	408	2,874
Other cost reduction activities for the period			81	309
Payments and non-cash item adjustment			(1,855)	(2,465)
Restructuring and Severance Ending Balance	$ 11	$ 1,867	$ 11	$ 1,867