Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=jxsb_OneToFourFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=jxsb_AgriculturalRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=jxsb_AgriculturalPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

LOAN PORTFOLIO COMPOSITION - Loans Modified as Troubled Debt Restructurings (Details 7)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($) Loan	Sep. 30, 2015 USD ($) Loan	Sep. 30, 2016 USD ($) Loan	Sep. 30, 2015 USD ($) Loan
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan	2		3	4
Troubled debt restructurings, recorded investment \| $	$ 937,353		$ 977,979	$ 168,466
Real estate loans \| One-to-four family residential
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan			1	1
Troubled debt restructurings, recorded investment \| $			$ 40,626	$ 100,492
Real estate loans \| Commercial real estate
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan	1		1
Troubled debt restructurings, recorded investment \| $	$ 719,022		$ 719,022
Real estate loans \| Agricultural real estate
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan
Troubled debt restructurings, recorded investment \| $
Real estate loans \| Home equity
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan				1
Troubled debt restructurings, recorded investment \| $				$ 1,996
Commercial loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan	1		1
Troubled debt restructurings, recorded investment \| $	$ 218,331		$ 218,331
Agricultural loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan
Troubled debt restructurings, recorded investment \| $
Consumer loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification \| Loan				2
Troubled debt restructurings, recorded investment \| $				$ 65,978