Employee Benefit Plans And Stock-Based Compensation Employee Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Postemployment Benefits [Abstract]
Service cost	$ 252	$ 227
Interest cost	37	78
Net periodic benefit cost included in operating loss	$ 289	$ 305