Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Prepaid Expenses and Other Current Assets [Abstract]
Inventory	$ 0	$ 139
Income tax receivable	237	310
Prepaid expenses	861	556
Other current assets	782	795
Total prepaid expenses and other current assets	$ 1,880	$ 1,800