Securities (Carrying Value of Securities Pledged as Collateral) (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 722,227
To secure public funds
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	441,379
To secure borrowings
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	111,978
Other securities pledged
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 168,870