Securities Available-for-Sale - Realized Gains (Losses) - Additional Information (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($)
Gross gains on sales and calls of securities	$ 230	$ 21	$ 1,024
Available-for-sale Securities, Gross Realized Losses	$ 428	$ 19	$ 524
Available-for-sale, securities in unrealized loss positions, qualitative disclosure, number of positions, total \| security	198	552
Securities available-for-sale	$ 592,378	$ 569,942
Investment securities available for sale	600,799	$ 560,479
States and Political Subdivisions [Member]
Securities available-for-sale	$ 188,265
U.S. Government Agencies [Member]
Number Of Securities With Realized Gross Gains \| security	74	11
Gross gains on sales and calls of securities	$ 230,000	$ 21,000
Securities available-for-sale	12,125	15,553
Investment securities available for sale	$ 12,145	$ 15,212
Other Securities [Member]
Number Of Securities With Unrealized Gross Losses \| security	108	8
Available-for-sale Securities, Gross Realized Losses	$ 428,000	$ 19,000
States and Political Subdivisions [Member]
Investment securities available for sale	$ 2,200

Total number of securities with realized gross gains as on the balance sheet date.

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Total number of securities with unrealized gross losses as on the balance sheet date.

+ References

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount 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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Amount of realized gain 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 realized 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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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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