Restructuring Activity Recorded in Operating Expenses and Accrued Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring expense incurred			$ 7,756
Restructuring amounts accrued, ending balance	$ 357
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring amounts accrued, beginning balance	0	$ 587
Restructuring expense incurred	3,560	0
Restructuring amounts paid	(3,203)	(587)
Restructuring amounts accrued, ending balance	$ 357	$ 0	$ 587