Other Assets and Liabilities - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Liabilities Disclosure [Abstract]
Valued-added tax recoverable	$ 341	$ 1,051
Prepaid and other expenses	1,018	2,116
Guarantee from Armistice	318	454
Income tax receivable (see Note 14)	18,615	536
Receivable from Exela (see Note 4)	16,500	0
Short-term deposit	1,477	0
Other	457	107
Total	$ 38,726	$ 4,264