Property and Equipment

12 Months Ended

Dec. 31, 2017

Property Plant And Equipment [Abstract]

Property and Equipment

7. Property and Equipment

Property and equipment consist of the following (in thousands):

	Estimated Useful	December 31,
	Life (In years)	2017			2016
Manufacturing equipment	5-14	$	12,104		$	10,086
Lab equipment	5-13		6,686			6,280
Computer equipment	3		4,760			4,010
Furniture and fixtures	3-13		1,629			1,566
Leasehold improvements	5-8(1)		10,873			8,942
Assets in progress			1,176			2,298
			37,228			33,182
Less accumulated depreciation and amortization			(20,609	)		(16,008	)
Total		$	16,619		$	17,174

(1) Leasehold improvements are amortized over the remaining life of the initial lease term or the estimated useful lives of the assets, whichever is shorter.

Depreciation and amortization expense on property and equipment was $3.2 million, $2.3 million and $1.4 million for the years ended December 31, 2017, 2016 and 2015, respectively.