Securities (Securities in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Mar. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	5	7
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 37,009	$ 61,514
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (215)	$ (192)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	8	34
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 19,547	$ 289,468
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (4,925)	$ (4,708)
Number of securities in a continuous unrealized loss position total | security	13	41
Fair value of securities in a continuous unrealized loss position total	$ 56,556	$ 350,982
Unrealized losses of securities in a continuous unrealized loss position total	$ (5,140)	$ (4,900)
Obligations of U.S. government-sponsored enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	1	3
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 24,831	$ 20,364
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (169)	$ (136)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	0	3
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ 49,902
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ (97)
Number of securities in a continuous unrealized loss position total | security	1	6
Fair value of securities in a continuous unrealized loss position total	$ 24,831	$ 70,266
Unrealized losses of securities in a continuous unrealized loss position total	$ (169)	$ (233)
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	4	4
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 12,178	$ 41,150
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (46)	$ (56)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	0	23
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ 216,804
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ (2,908)
Number of securities in a continuous unrealized loss position total | security	4	27
Fair value of securities in a continuous unrealized loss position total	$ 12,178	$ 257,954
Unrealized losses of securities in a continuous unrealized loss position total	$ (46)	$ (2,964)
Individual name issuer trust preferred debt securities
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	0	0
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Number of securities in a continuous unrealized loss position for 12 months or longer | security	5	5
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 11,096	$ 12,579
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (2,232)	$ (745)
Number of securities in a continuous unrealized loss position total | security	5	5
Fair value of securities in a continuous unrealized loss position total	$ 11,096	$ 12,579
Unrealized losses of securities in a continuous unrealized loss position total	$ (2,232)	$ (745)
Corporate bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	0	0
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 0
Number of securities in a continuous unrealized loss position for 12 months or longer | security	3	3
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 8,451	$ 10,183
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (2,693)	$ (958)
Number of securities in a continuous unrealized loss position total | security	3	3
Fair value of securities in a continuous unrealized loss position total	$ 8,451	$ 10,183
Unrealized losses of securities in a continuous unrealized loss position total	$ (2,693)	$ (958)