Summary of Significant Accounting Policies (Schedule of Other, Net) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Interest and dividend income	$ 6,074	$ 12,590	$ 11,349
Net gains (losses) recognized on investment securities	1,818	7,440	(9,570)
Net periodic benefit cost other than the service costs	(3,618)	(2,298)	(1,020)
Credit loss expense	12,828	0	0
Other income	3,098	3,573	4
Other, net	$ (5,456)	$ 21,305	$ 763