Income Tax Expense - Deferred Income Tax (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 111,220	$ 108,095
Tax loss on liquidation of subsidiary	2,501	4,029
Equity compensation	4,067	4,449
Non-deductible reserves	905	447
Total deferred tax assets	118,693	117,020
Valuation allowance	(118,583)	(116,200)	$ (103,185)	$ (100,832)
Net deferred tax assets	110	820
Deferred tax liabilities:
Financial liabilities	100	757
Property, plant and equipment	10	63
Total deferred tax liability	110	820
Deferred tax, net	$ 0	$ 0