<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.7.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>312</ContextCount>
  <ElementCount>394</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>70</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>6</UnitCount>
  <MyReports>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00090 - Document - Document And Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DocumentDocumentAndEntityInformation</Role>
      <ShortName>Document And Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00100 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00105 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00200 - Statement - Consolidated Statements Of Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedStatementsOfIncome</Role>
      <ShortName>Consolidated Statements Of Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00300 - Statement - Consolidated Statements Of Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedStatementsOfComprehensiveIncome</Role>
      <ShortName>Consolidated Statements Of Comprehensive Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00305 - Statement - Consolidated Statements Of Comprehensive Income (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedStatementsOfComprehensiveIncomeParenthetical</Role>
      <ShortName>Consolidated Statements Of Comprehensive Income (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00400 - Statement - Consolidated Statement Of Changes In Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedStatementOfChangesInStockholdersEquity</Role>
      <ShortName>Consolidated Statement Of Changes In Stockholders' Equity</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00500 - Statement - Consolidated Statements Of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/StatementConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements Of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>10101 - Disclosure - Summary Of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPolicies</Role>
      <ShortName>Summary Of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>10201 - Disclosure - Regulatory Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryMatters</Role>
      <ShortName>Regulatory Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>10301 - Disclosure - Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecurities</Role>
      <ShortName>Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>10401 - Disclosure - Loans And Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeases</Role>
      <ShortName>Loans And Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>10501 - Disclosure - Fair Value</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValue</Role>
      <ShortName>Fair Value</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>10601 - Disclosure - Subordinated Debentures</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSubordinatedDebentures</Role>
      <ShortName>Subordinated Debentures</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>10701 - Disclosure - Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureStockBasedCompensation</Role>
      <ShortName>Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>10801 - Disclosure - Regulatory Capital Matters</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMatters</Role>
      <ShortName>Regulatory Capital Matters</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>10901 - Disclosure - Derivative Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureDerivativeInstruments</Role>
      <ShortName>Derivative Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>11001 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureIncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>11101 - Disclosure - Accumulated Other Comprehensive Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureAccumulatedOtherComprehensiveIncome</Role>
      <ShortName>Accumulated Other Comprehensive Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>11201 - Disclosure - Preferred Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosurePreferredStock</Role>
      <ShortName>Preferred Stock</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>11301 - Disclosure - Common Stock Warrants</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureCommonStockWarrants</Role>
      <ShortName>Common Stock Warrants</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>20102 - Disclosure - Summary of Significant Accounting Policies (Policy)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicy</Role>
      <ShortName>Summary of Significant Accounting Policies (Policy)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>30103 - Disclosure - Summary Of Significant Accounting Policies (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>Summary Of Significant Accounting Policies (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>30303 - Disclosure - Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</Role>
      <ShortName>Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecurities</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>30403 - Disclosure - Loans And Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</Role>
      <ShortName>Loans And Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeases</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>30503 - Disclosure - Fair Value (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueTables</Role>
      <ShortName>Fair Value (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValue</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>30703 - Disclosure - Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationTables</Role>
      <ShortName>Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureStockBasedCompensation</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>30803 - Disclosure - Regulatory Capital Matters (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMattersTables</Role>
      <ShortName>Regulatory Capital Matters (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMatters</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>30903 - Disclosure - Derivative Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureDerivativeInstrumentsTables</Role>
      <ShortName>Derivative Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureDerivativeInstruments</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>31003 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureIncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureIncomeTaxes</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>31103 - Disclosure - Accumulated Other Comprehensive Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureAccumulatedOtherComprehensiveIncomeTables</Role>
      <ShortName>Accumulated Other Comprehensive Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureAccumulatedOtherComprehensiveIncome</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>40101 - Disclosure - Summary of Significant Accounting Policies (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesNarrativeDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicy</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>40102 - Disclosure - Summary Of Significant Accounting Policies (Earnings Per Common Share) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesEarningsPerCommonShareDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Earnings Per Common Share) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>40103 - Disclosure - Summary Of Significant Accounting Policies (Anti-Dilutive Common Shares) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAntiDilutiveCommonSharesDetails</Role>
      <ShortName>Summary Of Significant Accounting Policies (Anti-Dilutive Common Shares) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>40201 - Disclosure - Regulatory Matters (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryMattersDetails</Role>
      <ShortName>Regulatory Matters (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureRegulatoryMatters</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>40301 - Disclosure - Securities (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesNarrativeDetails</Role>
      <ShortName>Securities (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>40302 - Disclosure - Securities (Amortized Cost And Fair Value Of Available-For-Sale Securities Portfolio) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesAmortizedCostAndFairValueOfAvailableForSaleSecuritiesPortfolioDetails</Role>
      <ShortName>Securities (Amortized Cost And Fair Value Of Available-For-Sale Securities Portfolio) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>40303 - Disclosure - Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesAmortizedCostAndFairValueOfDebtSecuritiesByContractualMaturityDetails</Role>
      <ShortName>Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>40304 - Disclosure - Securities (Fair Value Of Securities Pledged) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesFairValueOfSecuritiesPledgedDetails</Role>
      <ShortName>Securities (Fair Value Of Securities Pledged) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>40305 - Disclosure - Securities (Securities With Unrealized Losses) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSecuritiesSecuritiesWithUnrealizedLossesDetails</Role>
      <ShortName>Securities (Securities With Unrealized Losses) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSecuritiesTables</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>40401 - Disclosure - Loans And Leases (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesNarrativeDetails</Role>
      <ShortName>Loans And Leases (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>40402 - Disclosure - Loans And Leases (Recorded Investment In Loans By Portfolio Segment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesRecordedInvestmentInLoansByPortfolioSegmentDetails</Role>
      <ShortName>Loans And Leases (Recorded Investment In Loans By Portfolio Segment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>40403 - Disclosure - Loans And Leases (Activity In ALLL By Portfolio Segment) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesActivityInAlllByPortfolioSegmentDetails</Role>
      <ShortName>Loans And Leases (Activity In ALLL By Portfolio Segment) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>40404 - Disclosure - Loans And Leases (Balance In ALLL And Recorded Investment In Loans By Portfolio Segment And Based On Impairment Method) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesBalanceInAlllAndRecordedInvestmentInLoansByPortfolioSegmentAndBasedOnImpairmentMethodDetails</Role>
      <ShortName>Loans And Leases (Balance In ALLL And Recorded Investment In Loans By Portfolio Segment And Based On Impairment Method) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>40405 - Disclosure - Loans And Leases (Individually Evaluated For Impairment By Class Of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesIndividuallyEvaluatedForImpairmentByClassOfLoansDetails</Role>
      <ShortName>Loans And Leases (Individually Evaluated For Impairment By Class Of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>45</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>40406 - Disclosure - Loans And Leases (Recorded Investment In Nonperforming Loans By Class Of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesRecordedInvestmentInNonperformingLoansByClassOfLoansDetails</Role>
      <ShortName>Loans And Leases (Recorded Investment In Nonperforming Loans By Class Of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>46</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>40407 - Disclosure - Loans And Leases (Aging Of Recorded Investment In Past Due Loans By Class Of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesAgingOfRecordedInvestmentInPastDueLoansByClassOfLoansDetails</Role>
      <ShortName>Loans And Leases (Aging Of Recorded Investment In Past Due Loans By Class Of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>47</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>40408 - Disclosure - Loans And Leases (Loans Modified As TDRs By Class Of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesLoansModifiedAsTdrsByClassOfLoansDetails</Role>
      <ShortName>Loans And Leases (Loans Modified As TDRs By Class Of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>40409 - Disclosure - Loans And Leases (Recorded Investment In Loans By Risk Category And Class Of Loans) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesRecordedInvestmentInLoansByRiskCategoryAndClassOfLoansDetails</Role>
      <ShortName>Loans And Leases (Recorded Investment In Loans By Risk Category And Class Of Loans) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureLoansAndLeasesTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>40501 - Disclosure - Fair Value (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueNarrativeDetails</Role>
      <ShortName>Fair Value (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>40502 - Disclosure - Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis, Including Financial Assets And Liabilities) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisIncludingFinancialAssetsAndLiabilitiesDetails</Role>
      <ShortName>Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis, Including Financial Assets And Liabilities) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>40503 - Disclosure - Fair Value (Assets Measured At Fair Value On A Non-Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueAssetsMeasuredAtFairValueOnNonRecurringBasisDetails</Role>
      <ShortName>Fair Value (Assets Measured At Fair Value On A Non-Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>52</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>40504 - Disclosure - Fair Value (Financial Instruments Measured At Fair Value On A Non-Recurring Basis) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueFinancialInstrumentsMeasuredAtFairValueOnNonRecurringBasisDetails</Role>
      <ShortName>Fair Value (Financial Instruments Measured At Fair Value On A Non-Recurring Basis) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>53</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>40505 - Disclosure - Fair Value (Aggregate Fair Value, Contractual Balance (Including Accrued Interest) And Gain Or Loss) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueAggregateFairValueContractualBalanceIncludingAccruedInterestAndGainOrLossDetails</Role>
      <ShortName>Fair Value (Aggregate Fair Value, Contractual Balance (Including Accrued Interest) And Gain Or Loss) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>40506 - Disclosure - Fair Value (Amount Of Gains And Losses From Changes In Fair Value Included In Earnings) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueAmountOfGainsAndLossesFromChangesInFairValueIncludedInEarningsDetails</Role>
      <ShortName>Fair Value (Amount Of Gains And Losses From Changes In Fair Value Included In Earnings) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>55</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>40507 - Disclosure - Fair Value (Carrying Amounts And Estimated Fair Values Of Financial Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureFairValueCarryingAmountsAndEstimatedFairValuesOfFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value (Carrying Amounts And Estimated Fair Values Of Financial Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureFairValueTables</ParentRole>
      <Position>56</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>40601 - Disclosure - Subordinated Debentures (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureSubordinatedDebenturesDetails</Role>
      <ShortName>Subordinated Debentures (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureSubordinatedDebentures</ParentRole>
      <Position>57</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>40701 - Disclosure - Stock-Based Compensation (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationTables</ParentRole>
      <Position>58</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>40702 - Disclosure - Stock-Based Compensation (Summary Of Stock Option Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation (Summary Of Stock Option Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationTables</ParentRole>
      <Position>59</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>40703 - Disclosure - Stock-Based Compensation (Nonvested Restricted Shares Activity) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationNonvestedRestrictedSharesActivityDetails</Role>
      <ShortName>Stock-Based Compensation (Nonvested Restricted Shares Activity) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureStockBasedCompensationTables</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>40801 - Disclosure - Regulatory Capital Matters (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMattersNarrativeDetails</Role>
      <ShortName>Regulatory Capital Matters (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMattersTables</ParentRole>
      <Position>61</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>40802 - Disclosure - Regulatory Capital Matters (Actual And Required Capital Amounts And Ratios Of CFBank) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMattersActualAndRequiredCapitalAmountsAndRatiosOfCfbankDetails</Role>
      <ShortName>Regulatory Capital Matters (Actual And Required Capital Amounts And Ratios Of CFBank) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureRegulatoryCapitalMattersTables</ParentRole>
      <Position>62</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>40901 - Disclosure - Derivative Instruments (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureDerivativeInstrumentsNarrativeDetails</Role>
      <ShortName>Derivative Instruments (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureDerivativeInstrumentsTables</ParentRole>
      <Position>63</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>40902 - Disclosure - Derivative Instruments (Summary Of Derivative Instruments) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureDerivativeInstrumentsSummaryOfDerivativeInstrumentsDetails</Role>
      <ShortName>Derivative Instruments (Summary Of Derivative Instruments) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureDerivativeInstrumentsTables</ParentRole>
      <Position>64</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>41001 - Disclosure - Income Taxes (Narrative) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureIncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes (Narrative) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>41002 - Disclosure - Income Taxes (Summary Of Differences Between Income Taxes At The Federal Statutory And Effective Tax Rate) (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureIncomeTaxesSummaryOfDifferencesBetweenIncomeTaxesAtFederalStatutoryAndEffectiveTaxRateDetails</Role>
      <ShortName>Income Taxes (Summary Of Differences Between Income Taxes At The Federal Statutory And Effective Tax Rate) (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureIncomeTaxesTables</ParentRole>
      <Position>66</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>41101 - Disclosure - Accumulated Other Comprehensive Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureAccumulatedOtherComprehensiveIncomeDetails</Role>
      <ShortName>Accumulated Other Comprehensive Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureAccumulatedOtherComprehensiveIncomeTables</ParentRole>
      <Position>67</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>41201 - Disclosure - Preferred Stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosurePreferredStockDetails</Role>
      <ShortName>Preferred Stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosurePreferredStock</ParentRole>
      <Position>68</Position>
    </Report>
    <Report instance="cfbk-20170331.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>41301 - Disclosure - Common Stock Warrants (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.cfbankonline.com/role/DisclosureCommonStockWarrantsDetails</Role>
      <ShortName>Common Stock Warrants (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.cfbankonline.com/role/DisclosureCommonStockWarrants</ParentRole>
      <Position>69</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>cfbk-20170331.xml</File>
    <File>cfbk-20170331.xsd</File>
    <File>cfbk-20170331_cal.xml</File>
    <File>cfbk-20170331_def.xml</File>
    <File>cfbk-20170331_lab.xml</File>
    <File>cfbk-20170331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
