Geographic Information and Concentrations (Details) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 2,250	$ 3,013	$ 18	$ 85	$ 172	$ 30	$ 2,320	$ 5,281	$ 2,607	$ 42,000
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									2,320
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue								5,281	287	42,000
HONG KONG
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue								1,500
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue								3,000		12,000
KKC | Japan | 2019 KKC Agreement
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue								300
KKC | Japan | 2017 KKC Agreement
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue								$ 500	$ 300	$ 30,000