Loans and Allowance for Loan Losses - ALL Roll Forward (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 5,105,000	$ 4,354,000	$ 4,354,000
Loans charged off	(25,000)		(306,000)
Recoveries of loans charged off	60,000		269,000
Provision (reallocation) charged to operating expense	12,450	137,557	788,000
Ending balance	5,152,000		5,105,000
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,369,000	1,906,000	1,906,000
Loans charged off	0		0
Recoveries of loans charged off	5,000		45,000
Provision (reallocation) charged to operating expense	(45,000)		418,000
Ending balance	2,329,000		2,369,000
Consumer Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,382,000	1,015,000	1,015,000
Loans charged off	0		(102,000)
Recoveries of loans charged off	17,000		76,000
Provision (reallocation) charged to operating expense	67,000		393,000
Ending balance	1,466,000		1,382,000
Construction and Land Development [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	717,000	627,000	627,000
Loans charged off	0		(14,000)
Recoveries of loans charged off	5,000		22,000
Provision (reallocation) charged to operating expense	(16,000)		82,000
Ending balance	706,000		717,000
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	520,000	777,000	777,000
Loans charged off	(3,000)		(35,000)
Recoveries of loans charged off	16,000		58,000
Provision (reallocation) charged to operating expense	25,000		(280,000)
Ending balance	558,000		520,000
Consumer and Other [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	117,000	$ 29,000	29,000
Loans charged off	(22,000)		(155,000)
Recoveries of loans charged off	17,000		68,000
Provision (reallocation) charged to operating expense	(19,000)		175,000
Ending balance	$ 93,000		$ 117,000

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section L
-Subsection 1

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 28
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-Name Accounting Standards Codification
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-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

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