Property and Equipment, Net (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Property and Equipment, Net [Abstract]
Property and equipment, gross		$ 47,571		$ 47,571		$ 47,398
Less: accumulated depreciation and amortization		(36,638)		(36,638)		(35,191)
Total property and equipment, net		10,933		10,933		12,207
Property Plant and Equipment Income Statement Disclosures [Abstract]
Depreciation and amortization		711	$ 765	1,447	$ 1,705
Machinery [Member]
Property and Equipment, Net [Abstract]
Property and equipment, gross		20,905		$ 20,905		20,681
Machinery [Member] | Minimum [Member]
Property and Equipment, Net [Abstract]
Useful lives				3 years
Machinery [Member] | Maximum [Member]
Property and Equipment, Net [Abstract]
Useful lives				15 years
Furniture and Fixtures [Member]
Property and Equipment, Net [Abstract]
Property and equipment, gross		1,150		$ 1,150		1,150
Furniture and Fixtures [Member] | Minimum [Member]
Property and Equipment, Net [Abstract]
Useful lives				3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property and Equipment, Net [Abstract]
Useful lives				15 years
Leasehold Improvements [Member]
Property and Equipment, Net [Abstract]
Property and equipment, gross	[1]	21,333		$ 21,333		21,333
Computer, Network Equipment and Software [Member]
Property and Equipment, Net [Abstract]
Property and equipment, gross		2,657		$ 2,657		2,579
Computer, Network Equipment and Software [Member] | Minimum [Member]
Property and Equipment, Net [Abstract]
Useful lives				3 years
Computer, Network Equipment and Software [Member] | Maximum [Member]
Property and Equipment, Net [Abstract]
Useful lives				7 years
Construction in Progress [Member]
Property and Equipment, Net [Abstract]
Property and equipment, gross		$ 1,526		$ 1,526		$ 1,655

[1] Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives.