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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Realized gains on investment securities									$ 1,144	$ 147	$ 9,399
Realized losses on investment securities									(1,111)	(102)	(1,754)
Net realized gains on investment securities									33	45	7,645
Unrealized gains on equity securities with readily determinable fair value									2,771	0	0
Unrealized losses on equity securities with readily determinable fair value									(4,910)	0	0
Net unrealized losses on equity securities with readily determinable fair value									(2,139)	0	0
Upward adjustments of equity securities without readily determinable fair values									325	0	0
Downward adjustments of equity securities without readily determinable fair values									0	0	0
Impairment of equity securities without readily determinable fair values									(1,117)	0	0
Adjustment and impairment, net, of equity securities without readily determinable fair values									(792)	0	0
Other than temporary impairment charges									0	0	0
(Losses) gains on investment securities, net	$ (2,649)	$ 90	$ 12	$ (351)	$ 14	$ 39	$ 47	$ (55)	(2,898)	45	7,645
Proceeds from sales of available-for-sale securities									214,196	344,674	2,194,278
Proceeds from sales of equity securities with readily determinable fair value									1,895	0	0
Proceeds from sales and capital distributions of equity securities without readily determinable fair value									$ 1,324	$ 0	$ 0