Restructuring and Severance (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring And Related Activities [Abstract]
Restructuring and Severance Beginning Balance			$ 633	$ 1,377
Restructuring expense incurred for the period	$ 160	$ 215	3,100	408
Other cost reduction activities for the period				81
Payments and non-cash item adjustment			(3,246)	(1,855)
Restructuring and Severance Ending Balance	$ 487	$ 11	$ 487	$ 11