Property, Plant and Equipment (Detail) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Land		$ 1,023	$ 1,023
Buildings		764	764
Leasehold improvements		22,782	16,259
Equipment		26,332	24,092
Furniture and fixtures		6,362	5,448
Construction in progress	[1]	6,826	12,906
Other		50
Total property, plant and equipment		64,139	60,492
Less - Accumulated depreciation		(29,613)	(28,312)
Total property, plant and equipment, net		$ 34,526	$ 32,180

[1] Construction in progress as of December 31, 2018 included $7.3 million for the buildout of our Marlborough facility, which was put into service and began depreciating on January 1, 2019, $2.1 million in capitalized internal-use software development costs and $2.1 million for a casting machine, among other projects.