Investments (Securities Gains (Losses)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments [Abstract]
Gross gains on retirement/sales of investment securities available for sale	$ 8,993	$ 353	$ 11,635
Gross losses on sales of investment securities available for sale	(1,878)	(2)	(7,342)
Realized gains on investment securities available for sale, net	$ 7,115	$ 351	$ 4,293