Commitments and Contingencies - Summary of Restructuring Activity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 196
Restructuring Expenses	9	$ 517
Cash Payments/ Adjustments	(42)
Ending Balance	163
Severance and Related Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	6
Restructuring Expenses	(1)
Cash Payments/ Adjustments	(5)
Ending Balance	0
Lease Terminations [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	190
Restructuring Expenses	10
Cash Payments/ Adjustments	(37)
Ending Balance	$ 163