Commitments and Contingencies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2003
Commitments and Contingencies
Operating Lease, Right-of-Use Asset	$ 6,600,000	$ 6,900,000
Operating Lease, Liability	6,949,000	7,000,000.0
Operating Lease, Payments	1,737,000
Lease, Cost	$ 1,752,000	$ 1,801,000	$ 1,603,000
Option to extend	true
Operating Lease, Weighted Average Remaining Lease Term	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	4.40%
Contingent cash payment				$ 1,000,000