Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 111,674	$ 103,101
Less: accumulated depreciation and amortization	(84,720)	(72,684)
Property and equipment, net	26,954	30,417
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment at cost	83,900	76,048
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment at cost	6,377	6,749
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment at cost	$ 21,397	$ 20,304