Investment Securities Available-for-Sale - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Federal Reserve and Federal Home Loan Bank stock	$ 40,018		$ 40,018		$ 35,194
Allowance for Credit Losses	$ 138		$ 138		0
Debt securities as percentage of total investment securities	99.90%		99.90%
Debt securities weighted average duration			3 years 1 month 6 days
Proceeds from sale/call of available-for-sale securities			$ 119,988	$ 42,143
Holdings of securities of any one issuer	10.00%		10.00%
Gross realized gains on sales of investment securities			$ 1,500	1,500
Noninterest income	$ 12,495	$ 6,360	17,965	12,651
Gross realized losses on sales of investment			0	$ 0
Other Assets
Accrued interest on available for sale securities	2,700		2,700		3,200
Interest Rate Swap
Noninterest income			829
Collateral Pledged
Available-for-sale securities pledged as collateral	$ 346,000		$ 346,000		$ 378,000

Amount of realized gain on investment in debt and equity securities.

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Amount of realized loss on investment in debt and equity securities.

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The total percentage of debt securities.

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Period of time between issuance and maturity of debt securities, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Percent of holdings of securities of any one issuer, other than the U.S. Government and U.S. agency securities, which exceeded shareholders equity.

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Interest, dividends, rents, ancillary and other revenues earned but not yet received by the entity on its investments.

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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 restricted 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 Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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Amount of cash inflow from maturity, prepayment and call of 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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