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Federal Funds Purchased and Securities Sold Under Agreement to Repurchase - Daily Securities Sold under Agreement to Repurchase (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period	$ 29,300
Daily Securities Sold Under Agreement to Repurchase [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period	$ 1,062	$ 1,899
Weighted Average Rate End of Period	0.70%	1.08%
Maximum Amount Borrowings Outstanding Month End	$ 1,991	$ 2,568
Approximate Average Outstanding in Period	$ 1,514	$ 1,765
Approximate Weighted Average Interest Rate For the Period	0.43%	1.00%
Term CDs Sold Under Agreement to Repurchase [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period	$ 28,206	$ 28,340
Weighted Average Rate End of Period	1.00%	1.00%
Maximum Amount Borrowings Outstanding Month End	$ 28,362	$ 29,261
Approximate Average Outstanding in Period	$ 28,315	$ 28,379
Approximate Weighted Average Interest Rate For the Period	2.56%	2.52%

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Securities sold under agreements to repurchase weighted average interest rate.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(m)(1)(i))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section 55
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-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(m)(1)(ii)(A)(i))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section 50
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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