Investment Securities (Credit Quality Information) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 549,096	$ 559,455
Speculative
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	0	$ 0
Aaa
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	137,358
Aa1
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	1,473
A3
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	4,000
Baa1
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	4,000
Baa2
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	500
Baa3
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	500
NR
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	401,265
U.S. Government agencies
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	146,699
U.S. Government agencies | Aaa
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	137,358
U.S. Government agencies | NR
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	9,341
Mortgage-backed
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	389,924
Mortgage-backed | NR
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	389,924
States and political subdivisions
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	1,473
States and political subdivisions | Aa1
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	1,473
Other debt securities
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	11,000
Other debt securities | A3
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	4,000
Other debt securities | Baa1
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	4,000
Other debt securities | Baa2
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	500
Other debt securities | Baa3
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	500
Other debt securities | NR
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 2,000