Restructuring - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) Floor
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 4,562
Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Cost incurred related to workforce reduction	$ 2,300
Corvallis Plan [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring, initiation date	2016-03
Restructuring, completion date	Dec. 31, 2016
Number of floors | Floor	2
Restructuring expenses	$ 1,400
Minimum lease payment obligation	$ 6,400
Corvallis Plan [Member] | Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Percentage of workforce reduced	19.00%
Estimated remaining restructuring expenses	$ 200
Corvallis Plan [Member] | Facility Closing [Member]
Restructuring Cost And Reserve [Line Items]
Number of floor closed | Floor	1
Cambridge Plan [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring, initiation date	2016-08
Restructuring, completion date	Oct. 31, 2016
Cambridge Plan [Member] | Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Percentage of workforce reduced	6.00%
Restructuring expenses	$ 600