Securities (Securities in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($) security
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	7	13
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 61,514	$ 48,258
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (192)	$ (448)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	34	77
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 289,468	$ 617,932
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (4,708)	$ (23,948)
Number of securities in a continuous unrealized loss position total | security	41	90
Fair value of securities in a continuous unrealized loss position total	$ 350,982	$ 666,190
Unrealized losses of securities in a continuous unrealized loss position total	$ (4,900)	$ (24,396)
Obligations of U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	3	0
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 20,364	$ 0
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (136)	$ 0
Number of securities in a continuous unrealized loss position for 12 months or longer | security	3	16
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 49,902	$ 157,032
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (97)	$ (4,467)
Number of securities in a continuous unrealized loss position total | security	6	16
Fair value of securities in a continuous unrealized loss position total	$ 70,266	$ 157,032
Unrealized losses of securities in a continuous unrealized loss position total	$ (233)	$ (4,467)
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	4	10
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 41,150	$ 47,060
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (56)	$ (439)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	23	51
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 216,804	$ 438,701
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (2,908)	$ (16,178)
Number of securities in a continuous unrealized loss position total | security	27	61
Fair value of securities in a continuous unrealized loss position total	$ 257,954	$ 485,761
Unrealized losses of securities in a continuous unrealized loss position total	$ (2,964)	$ (16,617)
Individual name issuer trust preferred debt securities [Member]
Schedule of Available for Sale and Held to Maturity Securities [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	$ 12,579	$ 11,772
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (745)	$ (1,535)
Number of securities in a continuous unrealized loss position total | security	5	5
Fair value of securities in a continuous unrealized loss position total	$ 12,579	$ 11,772
Unrealized losses of securities in a continuous unrealized loss position total	$ (745)	$ (1,535)
Corporate bonds [Member]
Schedule of Available for Sale and Held to Maturity Securities [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	0	3
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ 1,198
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ 0	$ (9)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	3	5
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 10,183	$ 10,427
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (958)	$ (1,768)
Number of securities in a continuous unrealized loss position total | security	3	8
Fair value of securities in a continuous unrealized loss position total	$ 10,183	$ 11,625
Unrealized losses of securities in a continuous unrealized loss position total	$ (958)	$ (1,777)