Property and Equipment - Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 6,546	$ 5,882	$ 4,087
Cost of sales
Property, Plant and Equipment [Line Items]
Depreciation expense	1,965	1,757	1,417
Selling, general and administrative
Property, Plant and Equipment [Line Items]
Depreciation expense	4,223	3,760	2,354
Research and development
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 358	$ 365	$ 316