Securities (Securities in a Continuous Unrealized Loss Position) (Details) $ in Thousands	Jun. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Number of securities in a continuous unrealized loss position for less than 12 months | security	51	22
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 544,708	$ 171,139
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (8,006)	$ (672)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	10	8
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 29,635	$ 22,597
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (1,335)	$ (1,897)
Number of securities in a continuous unrealized loss position total | security	61	30
Fair value of securities in a continuous unrealized loss position total	$ 574,343	$ 193,736
Unrealized losses of securities in a continuous unrealized loss position total	$ (9,341)	$ (2,569)
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	10	6
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 102,856	$ 63,856
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (2,044)	$ (145)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	0	0
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ 0
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ 0	$ 0
Number of securities in a continuous unrealized loss position total | security	10	6
Fair value of securities in a continuous unrealized loss position total	$ 102,856	$ 63,856
Unrealized losses of securities in a continuous unrealized loss position total	$ (2,044)	$ (145)
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	41	16
Fair value of securities in a continuous unrealized loss position for less than 12 months	$ 441,852	$ 107,283
Unrealized losses of securities in a continuous unrealized loss position for less than 12 months	$ (5,962)	$ (527)
Number of securities in a continuous unrealized loss position for 12 months or longer | security	2	0
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 6,349	$ 0
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (113)	$ 0
Number of securities in a continuous unrealized loss position total | security	43	16
Fair value of securities in a continuous unrealized loss position total	$ 448,201	$ 107,283
Unrealized losses of securities in a continuous unrealized loss position total	$ (6,075)	$ (527)
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	4	5
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 11,066	$ 12,669
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (294)	$ (672)
Number of securities in a continuous unrealized loss position total | security	4	5
Fair value of securities in a continuous unrealized loss position total	$ 11,066	$ 12,669
Unrealized losses of securities in a continuous unrealized loss position total	$ (294)	$ (672)
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	4	3
Fair value of securities in a continuous unrealized loss position for 12 months or longer	$ 12,220	$ 9,928
Unrealized losses of securities in a continuous unrealized loss position for 12 months or longer	$ (928)	$ (1,225)
Number of securities in a continuous unrealized loss position total | security	4	3
Fair value of securities in a continuous unrealized loss position total	$ 12,220	$ 9,928
Unrealized losses of securities in a continuous unrealized loss position total	$ (928)	$ (1,225)