Financial Derivatives (Schedule of Credit Derivatives) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Credit Default Swap, Selling Protection [Member]
Credit Derivatives [Line Items]
Fair Value	$ 1,816	$ 5,414
Notional value	71,877	132,176
Credit Default Swap, Buying Protection [Member]
Credit Derivatives [Line Items]
Fair Value of Purchased Credit Derivatives Offsetting Written Credit Derivatives	0	(3,248)
Notional value of purchased credit derivatives offsetting written credit derivatives	$ 0	$ (81,637)