Securities (Additional Information) (Details)	Sep. 30, 2020 USD ($) investment	Dec. 31, 2019 USD ($) investment	Dec. 31, 2009 USD ($)
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities pledged to secure repurchase agreements, public and trust deposits and other by law	$ 224,379,000	$ 245,664,000
Allowance for Credit Losses	0
Accrued interest receivable on debt securities available-for-sale	5,255,000
Original amount in non-controlling investment security in a single banking organization	353,000	$ 353,000	$ 1,350,000
Additional impairment on equity securities recognized through earnings	$ 0		$ 997,000
Equity Securities
Debt Securities, Available-for-sale [Line Items]
Number of non-controlling investments in a single banking organization \| investment	1	1

Debt Securities, Available-for-sale, Interest Receivable

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Carrying value of securities sold under agreements to repurchase and deposits received for securities loaned.

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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in equity security without readily determinable fair value.

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Amount of cumulative impairment loss on investment in equity security without readily determinable fair value.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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