Other Current Liabilities (Schedule of Other Current Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Current Liabilities [Abstract]
Operating lease liability, current	$ 652
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other current liabilities, total
Due to affiliate	$ 5	$ 164
Accrued professional fees	1,419	1,206
Pension and other postretirement liabilities	77	69
Income taxes payable	673
Accrued liabilities	57	56
Other current liabilities, total	$ 2,883	$ 1,495