Restructuring, Asset Impairment, and Transition Expenses - Reconciliation of Accrued Restructuring Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 1,971
Restructuring expense incurred	1,898	$ 1,553
Cash payments	(2,472)
Ending Balance	$ 1,397