Restructuring, Asset Impairment, and Transition Expenses - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1,198	$ 1,641	$ 3,096	$ 3,194
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	600		700
Consolidation costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	400		1,100
Other restructuring consolidation costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 200		$ 1,300