Investment Securities (Schedule of Available-for-Sale Investment Securities Gross Gains and Gross Losses Realized) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Realized gains on investment securities									$ 931	$ 1,144	$ 147
Realized losses on investment securities									(32)	(1,111)	(102)
Net realized gains on investment securities									899	33	45
Unrealized gains on equity securities with readily determinable fair value									3,057	2,771	0
Unrealized losses on equity securities with readily determinable fair value									(568)	(4,910)	0
Net unrealized gains (losses) on equity securities with readily determinable fair value									2,489	(2,139)	0
Upward adjustments of equity securities without readily determinable fair values									505	325	0
Downward adjustments of equity securities without readily determinable fair values									(106)	0	0
Impairment of equity securities without readily determinable fair values									(262)	(1,117)	0
Adjustment and impairment, net, of equity securities without readily determinable fair values									137	(792)	0
Other than temporary impairment charges									0	0	0
Gains (losses) on investment securities, net	$ 587	$ 710	$ 864	$ 1,364	$ (2,649)	$ 90	$ 12	$ (351)	3,525	(2,898)	45
Proceeds from sales of available-for-sale securities									972,253	214,196	344,674
Proceeds from sales of equity securities with readily determinable fair value									19,200	1,895	0
Proceeds from sales and capital distributions of equity securities without readily determinable fair value									$ 1,764	$ 1,324	$ 0