Income Taxes - Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Deferred income	$ 1,891	$ 1,937
Other	149	138
Tax loss carryforwards	32,487	29,648
Deferred tax assets, gross	34,527	31,723
Valuation allowance	(34,527)	(31,723)
Deferred tax assets, net of valuation allowance	0	0
Net deferred income taxes	$ 0	$ 0