Borrowed Funds - Short-term Borrowings, Long-term borrowings and Repurchase Agreements (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Borrowed funds
FHLB maximum borrowing capacity	$ 454,400
FHLB, remaining borrowing capacity	443,000
Short-term Borrowings from FHLB
Short-term Borrowings and Repurchase Agreements
Balance at end of period	0	$ 0
Average balance during the period	33,914	68,407
Maximum month-end balance	$ 130,047	$ 154,248
Weighted-average rate during the period	0.36%	0.58%
Weighted-average rate at end of period	0.00%	0.00%
Investment Securities
Short-term Borrowings and Repurchase Agreements
Investment securities held as collateral	$ 11,500	$ 10,700
Repurchase Agreements
Short-term Borrowings and Repurchase Agreements
Balance at end of period	11,139	10,266
Average balance during the period	10,677	9,856
Maximum month-end balance	$ 11,361	$ 10,505
Weighted-average rate during the period	0.14%	0.23%
Weighted-average rate at end of period	0.12%	0.14%

The average effective interest rate during the reporting period.

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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The carrying amount (fair value) as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities.

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For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, average borrowings during the period.

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