Disclosures about Fair Value of Assets - Estimated fair values of other financial instruments (Details 3) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Carrying Amount
Financial assets
Cash and cash equivalents	$ 12,909,924	$ 4,103,432
Interest-earning time deposits in banks	750,000	2,724,000
Other investments	55,481	62,223
Loans held for sale	503,003	539,000
Loans, net of allowance for loan losses	184,448,003	193,039,879
Federal Home Loan Bank stock	363,800	1,113,800
Interest receivable	1,588,545	1,715,676
Financial liabilities
Deposits	258,677,960	239,281,930
Short-term borrowings	7,135,182	15,131,710
Advances from borrowers for taxes and insurance	1,102,204	990,917
Interest payable	106,755	118,335
Unrecognized financial instruments (net of contract amount)
Commitments to originate loans
Letters of credit
Lines of credit
Fair Value \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets
Cash and cash equivalents	12,909,924	4,103,432
Interest-earning time deposits in banks	750,000	2,724,000
Other investments
Loans held for sale
Loans, net of allowance for loan losses
Federal Home Loan Bank stock
Interest receivable
Financial liabilities
Deposits
Short-term borrowings
Advances from borrowers for taxes and insurance
Interest payable
Unrecognized financial instruments (net of contract amount)
Commitments to originate loans
Letters of credit
Lines of credit
Fair Value \| Significant Other Observable Inputs (Level 2)
Financial assets
Cash and cash equivalents
Interest-earning time deposits in banks
Other investments	55,481	62,223
Loans held for sale	503,003	539,000
Loans, net of allowance for loan losses
Federal Home Loan Bank stock	363,800	1,113,800
Interest receivable	1,588,545	1,715,676
Financial liabilities
Deposits	178,491,424	160,227,406
Short-term borrowings	7,135,182	6,631,710
Advances from borrowers for taxes and insurance	1,102,204	990,917
Interest payable	106,755	118,335
Unrecognized financial instruments (net of contract amount)
Commitments to originate loans
Letters of credit
Lines of credit
Fair Value \| Significant Unobservable Inputs (Level 3)
Financial assets
Cash and cash equivalents
Interest-earning time deposits in banks
Other investments
Loans held for sale
Loans, net of allowance for loan losses	183,941,877	193,006,301
Federal Home Loan Bank stock
Interest receivable
Financial liabilities
Deposits	81,241,011	80,300,060
Short-term borrowings		8,500,000
Advances from borrowers for taxes and insurance
Interest payable
Unrecognized financial instruments (net of contract amount)
Commitments to originate loans
Letters of credit
Lines of credit

Represents fair value of advance payments by borrowers for taxes and insurance.

No definition available.

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- Definition

Represents fair value portion of amount related to interest earning/bearing from time deposits in banks.

+ References

No definition available.

+ Details

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Namespace Prefix:	jxsb_
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- Definition

Represents interest payable, fair value disclosure.

+ References

No definition available.

+ Details

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- Definition

Represents interest receivable, fair value disclosure.

+ References

No definition available.

+ Details

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- Definition

Represents letters of credit fair value disclosure.

+ References

No definition available.

+ Details

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- References

No definition available.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

+ Details

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Period Type:	instant

- Definition

Fair value portion of arrangements with third parties, including, but not limited to, operating lease arrangement and arrangement in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(25))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

+ Details

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Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 325
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=29638263&loc=d3e39828-111592

+ Details

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- Definition

Fair value portion of contractual arrangement with a lender under which borrowings can be made up to a specific amount at any point in time.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Line-of-Credit Arrangement
-URI http://asc.fasb.org/extlink&oid=6517033

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Glossary Loan
-URI http://asc.fasb.org/extlink&oid=6517073

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	instant

- Definition

Value of the other investment not readily marketable determined by management based upon fair value methods, including pricing of similar securities and valuation techniques, that was used to record the investment for financial reporting purposes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 820
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35710923&loc=d3e45360-110995

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

+ References

No definition available.

+ Details

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