Securities - Credit Quality Indicator (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Investment and Mortgage-Backed Securities
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	$ 394,729
Investment and Mortgage-Backed Securities | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	42,146
Investment and Mortgage-Backed Securities | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	174,305
Investment and Mortgage-Backed Securities | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	90,183
Investment and Mortgage-Backed Securities | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	77,572
Investment and Mortgage-Backed Securities | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	10,523
Securities Investment | State, municipal and sovereign debt obligations
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	292,226
Securities Investment | State, municipal and sovereign debt obligations | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	31,053
Securities Investment | State, municipal and sovereign debt obligations | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	145,704
Securities Investment | State, municipal and sovereign debt obligations | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	85,435
Securities Investment | State, municipal and sovereign debt obligations | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	30,034
Securities Investment | State, municipal and sovereign debt obligations | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0
Securities Investment | Corporate debt securities
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	70,343
Securities Investment | Corporate debt securities | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0
Securities Investment | Corporate debt securities | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	7,534
Securities Investment | Corporate debt securities | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	4,748
Securities Investment | Corporate debt securities | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	47,538
Securities Investment | Corporate debt securities | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	10,523
Other
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	32,160
Other | AAA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	11,093
Other | AA
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	21,067
Other | A
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0
Other | BBB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0
Other | BB
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	$ 0