Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Short-term debt:
Current portion of long-term debt	$ 123	$ 219
Total short-term debt	123	219
Long-term debt:
Finance lease obligations	155	232
Other unsecured promissory notes	105	248
Total	260	480
Less: current portion of long-term debt	123	219
Total long-term debt	$ 137	$ 261