Investment Securities (Available-for-sale And Held-to-maturity Securities, Continuous Unrealized Loss Position) (Details) $ in Thousands	Mar. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	97	123
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 410,821	$ 259,287
12 months or longer, Fair Value	71,625	155,022
Total, Fair Value	482,446	414,309
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(16,362)	(647)
12 months or longer, Unrealized losses	(7,276)	(1,519)
Total, Unrealized losses	$ (23,638)	$ (2,166)
Held-to-maturity, continuous unrealized loss position [Abstract]
Number of securities | security		1
Held-to-maturity, continuous unrealized loss position, Fair Value [Abstract]
12 months or longer, Fair Value		$ 7,152
Total, Fair Value		7,152
Held-to-maturity, continuous unrealized loss position, Unrealized losses [Abstract]
12 months or longer, Unrealized losses		(2,067)
Total, Unrealized losses		$ (2,067)
U.S. Government Agency Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	3	5
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 2,678	$ 12,214
12 months or longer, Fair Value	3,852	3,986
Total, Fair Value	6,530	16,200
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(8)	(44)
12 months or longer, Unrealized losses	(124)	(133)
Total, Unrealized losses	$ (132)	$ (177)
Asset-backed Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	40	28
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 206,017	$ 115,909
12 months or longer, Fair Value	23,235	56,427
Total, Fair Value	229,252	172,336
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(12,465)	(275)
12 months or longer, Unrealized losses	(1,324)	(260)
Total, Unrealized losses	$ (13,789)	$ (535)
Taxable obligations of states and political subdivisions [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	1
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 2,498
Total, Fair Value	2,498
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(4)
Total, Unrealized losses	$ (4)
Residential Mortgage-backed Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	38	64
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 52,631	$ 58,682
12 months or longer, Fair Value	25,719	73,311
Total, Fair Value	78,350	131,993
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(1,240)	(114)
12 months or longer, Unrealized losses	(662)	(987)
Total, Unrealized losses	$ (1,902)	$ (1,101)
Collateralized Mortgage Obligation Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	6	22
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 21,012	$ 37,387
12 months or longer, Fair Value	12,566	18,136
Total, Fair Value	33,578	55,523
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(662)	(85)
12 months or longer, Unrealized losses	(310)	(123)
Total, Unrealized losses	$ (972)	$ (208)
Commercial Mortgage-backed Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	8	4
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
Less than 12 months, Fair Value	$ 125,985	$ 35,095
12 months or longer, Fair Value	1,101	3,162
Total, Fair Value	127,086	38,257
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
Less than 12 months, Unrealized losses	(1,983)	(129)
12 months or longer, Unrealized losses	(8)	(16)
Total, Unrealized losses	$ (1,991)	$ (145)
Corporate Debt Securities [Member]
Available-for-sale, continuous unrealized loss position [Abstract]
Number of securities | security	1
Available-for-sale, continuous unrealized loss position, Fair Value [Abstract]
12 months or longer, Fair Value	$ 5,152
Total, Fair Value	5,152
Available-for-sale, continuous unrealized loss position, Unrealized losses [Abstract]
12 months or longer, Unrealized losses	(4,848)
Total, Unrealized losses	$ (4,848)
Single Issuers [Member]
Held-to-maturity, continuous unrealized loss position [Abstract]
Number of securities | security		1
Held-to-maturity, continuous unrealized loss position, Fair Value [Abstract]
12 months or longer, Fair Value		$ 7,152
Total, Fair Value		7,152
Held-to-maturity, continuous unrealized loss position, Unrealized losses [Abstract]
12 months or longer, Unrealized losses		(2,067)
Total, Unrealized losses		$ (2,067)