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Allowance for Probable Loan Losses (Non-accrual Basis By Loan Class) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loan loss allowances, financing receivable past due
Non-accrual loans, total	$ 4,886,000	$ 15,791,000	$ 54,730,000
Reduced interest income on non-accrual loans	340,000	1,119,000	$ 977,000
Commercial
Loan loss allowances, financing receivable past due
Non-accrual loans, total	1,901,000	9,143,000
Commercial Real Estate:Other Construction and Land Development
Loan loss allowances, financing receivable past due
Non-accrual loans, total	938,000	2,092,000
Commercial Real Estate: Farmland and Commercial
Loan loss allowances, financing receivable past due
Non-accrual loans, total	1,208,000	3,509,000
Commercial Real Estate: Multifamily
Loan loss allowances, financing receivable past due
Non-accrual loans, total	165,000	507,000
Residential First Lien
Loan loss allowances, financing receivable past due
Non-accrual loans, total	670,000	347,000
Residential Junior Lien
Loan loss allowances, financing receivable past due
Non-accrual loans, total		171,000
Consumer
Loan loss allowances, financing receivable past due
Non-accrual loans, total	$ 4,000	$ 22,000

X

- Definition

Represents the reduction in interest income on recorded investment in financing receivables that are on nonaccrual status.

+ References

No definition available.

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- Definition

Amount of financing receivable on nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447

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