Investments In Securities and Fair Value (Schedule of Measurement Alternative Investments) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Measurement Alternative Investments
Beginning of Period	$ 7,899	$ 6,589
Amounts Impaired	0	0
Observable Changes	0	0
Purchases and Additional Commitments Paid	642	2,241
Sales, Returns of Capital and Other Reductions	(32)	(931)
End of Period	$ 8,509	$ 7,899