<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.4.0.6</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>71</ContextCount>
  <ElementCount>169</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>8</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>3</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000990 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>001000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedBalanceSheets</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>001010 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>002000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedStatementsOfOperations</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>003000 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/ConsolidatedStatementsOfComprehensiveOperations</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>004000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedStatementsOfStockholdersEquity</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>004010 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedStatementsOfStockholdersEquityParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>005000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CondensedConsolidatedStatementsOfCashFlows</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>006010 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>006020 - Disclosure - Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/Securities</Role>
      <ShortName>Securities</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>006030 - Disclosure - Loans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/Loans</Role>
      <ShortName>Loans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>006040 - Disclosure - Allowance for Loan and Lease Losses and Credit Disclosures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/AllowanceForLoanAndLeaseLossesAndCreditDisclosures</Role>
      <ShortName>Allowance for Loan and Lease Losses and Credit Disclosures</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>006050 - Disclosure - Office Buildings and Equipment</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/OfficeBuildingsAndEquipment</Role>
      <ShortName>Office Buildings and Equipment</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>006060 - Disclosure - Other Real Estate Owned</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/OtherRealEstateOwned</Role>
      <ShortName>Other Real Estate Owned</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>006070 - Disclosure - Goodwill and Core Deposit Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/GoodwillAndCoreDepositIntangibleAssets</Role>
      <ShortName>Goodwill and Core Deposit Intangible Assets</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>006080 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/Deposits</Role>
      <ShortName>Deposits</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>006090 - Disclosure - Borrowings</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/Borrowings</Role>
      <ShortName>Borrowings</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>006100 - Disclosure - Subordinated Debentures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/SubordinatedDebentures</Role>
      <ShortName>Subordinated Debentures</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>006110 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>006120 - Disclosure - Preferred Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/PreferredStock</Role>
      <ShortName>Preferred Stock</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>006130 - Disclosure - Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/RegulatoryMatters</Role>
      <ShortName>Regulatory Matters</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>006140 - Disclosure - Commitments, Off-Balance Sheet Risk, and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/CommitmentsOffBalanceSheetRiskAndContingencies</Role>
      <ShortName>Commitments, Off-Balance Sheet Risk, and Contingencies</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>006150 - Disclosure - Loss Per Share and Capital Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/LossPerShareAndCapitalMatters</Role>
      <ShortName>Loss Per Share and Capital Matters</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>006160 - Disclosure - Other Comprehensive Income (Loss)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/OtherComprehensiveIncomeLoss</Role>
      <ShortName>Other Comprehensive Income (Loss)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>006170 - Disclosure - Fair Value Measurement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/FairValueMeasurement</Role>
      <ShortName>Fair Value Measurement</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>006180 - Disclosure - Fair Values of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/FairValuesOfFinancialInstruments</Role>
      <ShortName>Fair Values of Financial Instruments</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>006190 - Disclosure - Parent Company Condensed Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/ParentCompanyCondensedFinancialStatements</Role>
      <ShortName>Parent Company Condensed Financial Statements</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>006200 - Disclosure - Quarterly Financial Data (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/QuarterlyFinancialDataUnaudited</Role>
      <ShortName>Quarterly Financial Data (Unaudited)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>006210 - Disclosure - Consent Order and Written Agreement</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/ConsentOrderAndWrittenAgreement</Role>
      <ShortName>Consent Order and Written Agreement</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>006220 - Disclosure - Management Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://norstatesbank.com/role/ManagementPlans</Role>
      <ShortName>Management Plans</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs>
    <Log type="Info">Process Flow-Through: 001000 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Mar. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 001010 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 002000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</Log>
    <Log type="Info">	Process Flow-Through: Removing column '9 Months Ended
Dec. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 003000 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE OPERATIONS</Log>
    <Log type="Info">	Process Flow-Through: Removing column '9 Months Ended
Dec. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 004010 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 005000 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</Log>
  </Logs>
  <InputFiles>
    <File>nsfc-20111231.xml</File>
    <File>nsfc-20111231.xsd</File>
    <File>nsfc-20111231_cal.xml</File>
    <File>nsfc-20111231_def.xml</File>
    <File>nsfc-20111231_lab.xml</File>
    <File>nsfc-20111231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
