Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	Feb. 17, 2017	Jan. 06, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Depreciation Expense			$ 1,700	$ 1,800	$ 2,400
Cash received from property, plant and equipment			120	$ 24	17
Furniture and Fixtures, Manufacturing Equipment and Laboratory Equipment
Property Plant And Equipment [Line Items]
Amount of divestiture of long-lived			$ 2,100
Land, Buildings and Improvements | California
Property Plant And Equipment [Line Items]
Amount of divestiture of long-lived		$ 17,300
Cash received from property, plant and equipment	$ 17,300
Net cash received from property, plant and equipment		16,700
Payments for commissions and other fees		$ 600
Carrying value of the asset held for sale					$ 16,700