2.4.0.8049 - Disclosure - INVESTMENTS - (Detail Textuals)truefalsefalse1false USDfalsefalse$Context_6ME__30-Jun-2013http://www.sec.gov/CIK0001484949duration2013-01-01T00:00:002013-06-30T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170pureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$2false USDfalsefalse$Context_6ME_30-Jun-2012http://www.sec.gov/CIK0001484949duration2012-01-01T00:00:002012-06-30T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$Context_As_Of__31-Dec-2012http://www.sec.gov/CIK0001484949instant2012-12-31T00:00:000001-01-01T00:00:00pureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 1us-gaap_ScheduleOfInvestmentsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Schedule Of Investments [Abstract]2false 2us-gaap_DepositLiabilitiesCollateralIssuedFinancialInstrumentsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse1916900019169000USD$falsetruefalse2falsefalsefalse00falsefalsefalse3truefalsefalse2437100024371000USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount of securities, mortgage loans, or other financial instruments pledged as collateral for deposits.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 405 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6479006&loc=d3e64164-112818 false2Securities pledged as collateral3false 2us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse74440007444000falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse1370600013706000falsefalsefalsexbrli:monetaryItemTypemonetaryAmount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security resale agreement between the entity and another party for the purchase and resale of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13(1)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=20225523&loc=SL20225862-175312 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=28370219&loc=SL20226008-175313 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 1 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=7472769&loc=d3e9760-107771 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(m)(1)(a)(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 false2Securities sold under agreements to repurchase4false 2us-gaap_AvailableForSaleSecuritiesGrossRealizedGainsus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse689000689000falsefalsefalse2truefalsefalse527000527000falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThis item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 false2Gross realized gains on sales of available-for-sale securities5false 2us-gaap_AvailableForSaleSecuritiesGrossRealizedLossesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse00falsefalsefalse2truefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryThis item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 false2Gross realized losses on sales of available-for-sale securities6false 2jxsb_DebtSecuritiesFairValuejxsb_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse6500000065000000USD$falsetruefalse2falsefalsefalse00falsefalsefalse3truefalsefalse2395600023956000USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount of debt securities in which the amortized cost basis exceeds the fair value.No definition available.false2Debt securities, fair value7false 2jxsb_PercentageOfAvailableForSaleSecuritiesDebtSecuritiesjxsb_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.5910.591falsefalsefalse2falsetruefalse00falsefalsefalse3truetruefalse0.2080.208falsefalsefalsenum:percentItemTypepureAmount of debt securities in which the amortized cost basis exceeds the fair value, as a percentage of total debt securities.No definition available.false0Percentage of available-for-sale investment portfoliofalseINVESTMENTS - (Detail Textuals) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.jacksonvillesavings.com/role/INVESTMENTSDetailTextuals37