Business Description and Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Description and Summary of Significant Accounting Policies
Income tax expense	$ (38)	$ 671
Income tax expense (% Change)	(105.70%)
Effective tax rate	(61.30%)	21.50%
Effective tax rate (% Change)	(385.10%)