<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>275</ContextCount>
  <ElementCount>381</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>78</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001002 - Statement - CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1002003 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1003004 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1004005 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>1005006 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>1006007 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2101101 - Disclosure - Organization</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/Organization</Role>
      <ShortName>Organization</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2102102 - Disclosure - Summary of Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SummaryofSignificantAccountingPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2105103 - Disclosure - Revenues</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/Revenues</Role>
      <ShortName>Revenues</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2108104 - Disclosure - Investment Securities</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/InvestmentSecurities</Role>
      <ShortName>Investment Securities</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2113105 - Disclosure - Accounts Receivable</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/AccountsReceivable</Role>
      <ShortName>Accounts Receivable</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2117106 - Disclosure - Loans to Bank Customers</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomers</Role>
      <ShortName>Loans to Bank Customers</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2124107 - Disclosure - Employee Stock-Based Compensation</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EmployeeStockBasedCompensation</Role>
      <ShortName>Employee Stock-Based Compensation</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2128108 - Disclosure - Deposits</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/Deposits</Role>
      <ShortName>Deposits</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2132109 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2134110 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2139111 - Disclosure - Stockholders' Equity</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/StockholdersEquity</Role>
      <ShortName>Stockholders' Equity</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2141112 - Disclosure - Earnings per Common Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EarningsperCommonShare</Role>
      <ShortName>Earnings per Common Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2145113 - Disclosure - Fair Value Measurements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueMeasurements</Role>
      <ShortName>Fair Value Measurements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2149114 - Disclosure - Fair Value of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueofFinancialInstruments</Role>
      <ShortName>Fair Value of Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2152115 - Disclosure - Leases</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/Leases</Role>
      <ShortName>Leases</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2157116 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2159117 - Disclosure - Significant Retailer Concentrations</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SignificantRetailerConcentrations</Role>
      <ShortName>Significant Retailer Concentrations</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>24</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2162118 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>25</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2203201 - Disclosure - Summary of Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SummaryofSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Summary of Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SummaryofSignificantAccountingPolicies</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2306301 - Disclosure - Revenues (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/RevenuesTables</Role>
      <ShortName>Revenues (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/Revenues</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2309302 - Disclosure - Investment Securities (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/InvestmentSecuritiesTables</Role>
      <ShortName>Investment Securities (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/InvestmentSecurities</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2314303 - Disclosure - Accounts Receivable (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/AccountsReceivableTables</Role>
      <ShortName>Accounts Receivable (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/AccountsReceivable</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2318304 - Disclosure - Loans to Bank Customers (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersTables</Role>
      <ShortName>Loans to Bank Customers (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/LoanstoBankCustomers</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2325305 - Disclosure - Employee Stock-Based Compensation (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EmployeeStockBasedCompensationTables</Role>
      <ShortName>Employee Stock-Based Compensation (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/EmployeeStockBasedCompensation</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2329306 - Disclosure - Deposits (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/DepositsTables</Role>
      <ShortName>Deposits (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/Deposits</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2335307 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/IncomeTaxes</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2342308 - Disclosure - Earnings per Common Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EarningsperCommonShareTables</Role>
      <ShortName>Earnings per Common Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/EarningsperCommonShare</ParentRole>
      <Position>34</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2346309 - Disclosure - Fair Value Measurements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueMeasurementsTables</Role>
      <ShortName>Fair Value Measurements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/FairValueMeasurements</ParentRole>
      <Position>35</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2350310 - Disclosure - Fair Value of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueofFinancialInstrumentsTables</Role>
      <ShortName>Fair Value of Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/FairValueofFinancialInstruments</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2353311 - Disclosure - Leases (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LeasesTables</Role>
      <ShortName>Leases (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/Leases</ParentRole>
      <Position>37</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2360312 - Disclosure - Significant Retailer Concentrations (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SignificantRetailerConcentrationsTables</Role>
      <ShortName>Significant Retailer Concentrations (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SignificantRetailerConcentrations</ParentRole>
      <Position>38</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2363313 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SegmentInformation</ParentRole>
      <Position>39</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2404401 - Disclosure - Summary of Significant Accounting Policies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SummaryofSignificantAccountingPoliciesDetails</Role>
      <ShortName>Summary of Significant Accounting Policies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SummaryofSignificantAccountingPoliciesPolicies</ParentRole>
      <Position>40</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Revenues (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/RevenuesDetails</Role>
      <ShortName>Revenues (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/RevenuesTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2410403 - Disclosure - Investment Securities - Gross Gains and Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/InvestmentSecuritiesGrossGainsandLossesDetails</Role>
      <ShortName>Investment Securities - Gross Gains and Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2411404 - Disclosure - Investment Securities - Continuous Unrealized Loss (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/InvestmentSecuritiesContinuousUnrealizedLossDetails</Role>
      <ShortName>Investment Securities - Continuous Unrealized Loss (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2412405 - Disclosure - Investment Securities - Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/InvestmentSecuritiesMaturitiesDetails</Role>
      <ShortName>Investment Securities - Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>2415406 - Disclosure - Accounts Receivable - Accounts Receivable, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/AccountsReceivableAccountsReceivableNetDetails</Role>
      <ShortName>Accounts Receivable - Accounts Receivable, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>2416407 - Disclosure - Accounts Receivable - Reserve For Uncollectible Overdrawn Accounts (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/AccountsReceivableReserveForUncollectibleOverdrawnAccountsDetails</Role>
      <ShortName>Accounts Receivable - Reserve For Uncollectible Overdrawn Accounts (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>2419408 - Disclosure - Loans to Bank Customers - Loan Summary (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersLoanSummaryDetails</Role>
      <ShortName>Loans to Bank Customers - Loan Summary (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>2420409 - Disclosure - Loans to Bank Customers - Nonperforming Loans (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersNonperformingLoansDetails</Role>
      <ShortName>Loans to Bank Customers - Nonperforming Loans (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>48</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>2421410 - Disclosure - Loans to Bank Customers - Credit Quality Indicators (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersCreditQualityIndicatorsDetails</Role>
      <ShortName>Loans to Bank Customers - Credit Quality Indicators (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>49</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>2422411 - Disclosure - Loans to Bank Customers - Troubled Debt Restructurings (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersTroubledDebtRestructuringsDetails</Role>
      <ShortName>Loans to Bank Customers - Troubled Debt Restructurings (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>50</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>2423412 - Disclosure - Loans to Bank Customers - Allowance for Loan Losses (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LoanstoBankCustomersAllowanceforLoanLossesDetails</Role>
      <ShortName>Loans to Bank Customers - Allowance for Loan Losses (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>51</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>2426413 - Disclosure - Employee Stock-Based Compensation - Narrative and Grant Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EmployeeStockBasedCompensationNarrativeandGrantActivityDetails</Role>
      <ShortName>Employee Stock-Based Compensation - Narrative and Grant Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>2427414 - Disclosure - Employee Stock-Based Compensation - Fair Value Assumptions (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EmployeeStockBasedCompensationFairValueAssumptionsDetails</Role>
      <ShortName>Employee Stock-Based Compensation - Fair Value Assumptions (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>2430415 - Disclosure - Deposits - Summary of Deposits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/DepositsSummaryofDepositsDetails</Role>
      <ShortName>Deposits - Summary of Deposits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>54</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>2431416 - Disclosure - Deposits - Contractual Maturities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/DepositsContractualMaturitiesDetails</Role>
      <ShortName>Deposits - Contractual Maturities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>55</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>2433417 - Disclosure - Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/DebtNarrativeDetails</Role>
      <ShortName>Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>56</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R57.htm</HtmlFileName>
      <LongName>2436418 - Disclosure - Income Taxes - Effective Tax Rate Reconciliation (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/IncomeTaxesEffectiveTaxRateReconciliationDetails</Role>
      <ShortName>Income Taxes - Effective Tax Rate Reconciliation (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>57</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R58.htm</HtmlFileName>
      <LongName>2437419 - Disclosure - Income Taxes - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/IncomeTaxesNarrativeDetails</Role>
      <ShortName>Income Taxes - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>58</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R59.htm</HtmlFileName>
      <LongName>2438420 - Disclosure - Income Taxes - Rollforward of Unrecognized Tax Benefits (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/IncomeTaxesRollforwardofUnrecognizedTaxBenefitsDetails</Role>
      <ShortName>Income Taxes - Rollforward of Unrecognized Tax Benefits (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>59</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R60.htm</HtmlFileName>
      <LongName>2440421 - Disclosure - Stockholders' Equity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/StockholdersEquityDetails</Role>
      <ShortName>Stockholders' Equity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/StockholdersEquity</ParentRole>
      <Position>60</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>2443422 - Disclosure - Earnings per Common Share - Basic Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EarningsperCommonShareBasicEarningsPerShareDetails</Role>
      <ShortName>Earnings per Common Share - Basic Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>61</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>2444423 - Disclosure - Earnings per Common Share - Antidilutive Shares (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/EarningsperCommonShareAntidilutiveSharesDetails</Role>
      <ShortName>Earnings per Common Share - Antidilutive Shares (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>62</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R63.htm</HtmlFileName>
      <LongName>2447424 - Disclosure - Fair Value Measurements - Fair Value Hierarchy (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueMeasurementsFairValueHierarchyDetails</Role>
      <ShortName>Fair Value Measurements - Fair Value Hierarchy (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>63</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R64.htm</HtmlFileName>
      <LongName>2448425 - Disclosure - Fair Value Measurements - Contingent Consideration Payable (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueMeasurementsContingentConsiderationPayableDetails</Role>
      <ShortName>Fair Value Measurements - Contingent Consideration Payable (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>64</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R65.htm</HtmlFileName>
      <LongName>2451426 - Disclosure - Fair Value of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/FairValueofFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/FairValueofFinancialInstrumentsTables</ParentRole>
      <Position>65</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R66.htm</HtmlFileName>
      <LongName>2454427 - Disclosure - Leases - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LeasesNarrativeDetails</Role>
      <ShortName>Leases - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>66</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>2455428 - Disclosure - Leases - Supplemental Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LeasesSupplementalInformationDetails</Role>
      <ShortName>Leases - Supplemental Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>67</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>2456429 - Disclosure - Leases - Maturities of Operating Leases (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/LeasesMaturitiesofOperatingLeasesDetails</Role>
      <ShortName>Leases - Maturities of Operating Leases (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>68</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R69.htm</HtmlFileName>
      <LongName>2458430 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/CommitmentsandContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/CommitmentsandContingencies</ParentRole>
      <Position>69</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R70.htm</HtmlFileName>
      <LongName>2461431 - Disclosure - Significant Retailer Concentrations (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SignificantRetailerConcentrationsDetails</Role>
      <ShortName>Significant Retailer Concentrations (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SignificantRetailerConcentrationsTables</ParentRole>
      <Position>70</Position>
    </Report>
    <Report instance="gdot-20200331.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R71.htm</HtmlFileName>
      <LongName>2464432 - Disclosure - Segment Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://mygreendot.com/role/SegmentInformationDetails</Role>
      <ShortName>Segment Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://mygreendot.com/role/SegmentInformationTables</ParentRole>
      <Position>71</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File doctype="10-Q" original="gdot-20200331.htm">gdot-20200331.htm</File>
    <File>exb103-gdotinducements.htm</File>
    <File>exb104-gdotinducementp.htm</File>
    <File>exb105-gdotinducementr.htm</File>
    <File>exb311-gdot03312020.htm</File>
    <File>exb312-gdot03312020.htm</File>
    <File>exb321-gdot03312020.htm</File>
    <File>exb322-gdot03312020.htm</File>
    <File>gdot-20200331.xsd</File>
    <File>gdot-20200331_cal.xml</File>
    <File>gdot-20200331_def.xml</File>
    <File>gdot-20200331_lab.xml</File>
    <File>gdot-20200331_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>gdot-20200331_g1.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://fasb.org/srt/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
