<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.23.3</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>331</ContextCount>
  <ElementCount>295</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>true</FootnotesReported>
  <SegmentCount>71</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>5</UnitCount>
  <MyReports>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0000001 - Document - Cover Page</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CoverPage</Role>
      <ShortName>Cover Page</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>0000002 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>0000003 - Statement - CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>0000004 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>0000005 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>0000006 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>0000007 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITYParenthetical</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>0000008 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS</Role>
      <ShortName>CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>0000009 - Disclosure - Condensed Consolidated Financial Statements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatements</Role>
      <ShortName>Condensed Consolidated Financial Statements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>0000010 - Disclosure - Revenue</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/Revenue</Role>
      <ShortName>Revenue</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>0000011 - Disclosure - Divestiture</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/Divestiture</Role>
      <ShortName>Divestiture</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>0000012 - Disclosure - Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/Debt</Role>
      <ShortName>Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>0000013 - Disclosure - Software and Other Intangible Assets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssets</Role>
      <ShortName>Software and Other Intangible Assets</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>0000014 - Disclosure - Stock-Based Compensation Plans</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlans</Role>
      <ShortName>Stock-Based Compensation Plans</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>0000015 - Disclosure - Common Stock and Treasury Stock</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CommonStockandTreasuryStock</Role>
      <ShortName>Common Stock and Treasury Stock</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>0000016 - Disclosure - Earnings (Loss) Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/EarningsLossPerShare</Role>
      <ShortName>Earnings (Loss) Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>0000017 - Disclosure - Other, Net</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/OtherNet</Role>
      <ShortName>Other, Net</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>0000018 - Disclosure - Segment Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SegmentInformation</Role>
      <ShortName>Segment Information</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>0000019 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>0000020 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CommitmentsandContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>20</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>995410 - Disclosure - Pay vs Performance Disclosure</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/PvpDisclosure</Role>
      <ShortName>Pay vs Performance Disclosure</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>21</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>995445 - Disclosure - Insider Trading Arrangements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements</Role>
      <ShortName>Insider Trading Arrangements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>22</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>9954471 - Disclosure - Condensed Consolidated Financial Statements (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatementsPolicies</Role>
      <ShortName>Condensed Consolidated Financial Statements (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>23</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>9954472 - Disclosure - Condensed Consolidated Financial Statements (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatementsTables</Role>
      <ShortName>Condensed Consolidated Financial Statements (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatements</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>9954473 - Disclosure - Revenue (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/RevenueTables</Role>
      <ShortName>Revenue (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/Revenue</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>9954474 - Disclosure - Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/DebtTables</Role>
      <ShortName>Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/Debt</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>9954475 - Disclosure - Software and Other Intangible Assets (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssetsTables</Role>
      <ShortName>Software and Other Intangible Assets (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssets</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>9954476 - Disclosure - Stock-Based Compensation Plans (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansTables</Role>
      <ShortName>Stock-Based Compensation Plans (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/StockBasedCompensationPlans</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>9954477 - Disclosure - Earnings (Loss) Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/EarningsLossPerShareTables</Role>
      <ShortName>Earnings (Loss) Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/EarningsLossPerShare</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>9954478 - Disclosure - Segment Information (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SegmentInformationTables</Role>
      <ShortName>Segment Information (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/SegmentInformation</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>9954479 - Disclosure - Condensed Consolidated Financial Statements - Schedule of Other Current Liabilities (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatementsScheduleofOtherCurrentLiabilitiesDetails</Role>
      <ShortName>Condensed Consolidated Financial Statements - Schedule of Other Current Liabilities (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>9954480 - Disclosure - Condensed Consolidated Financial Statements - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CondensedConsolidatedFinancialStatementsNarrativeDetails</Role>
      <ShortName>Condensed Consolidated Financial Statements - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>9954481 - Disclosure - Revenue - Schedule of Total Receivables, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/RevenueScheduleofTotalReceivablesNetDetails</Role>
      <ShortName>Revenue - Schedule of Total Receivables, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>9954482 - Disclosure - Revenue - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/RevenueNarrativeDetails</Role>
      <ShortName>Revenue - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>9954483 - Disclosure - Revenue - Schedule of Changes in Deferred Revenue (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/RevenueScheduleofChangesinDeferredRevenueDetails</Role>
      <ShortName>Revenue - Schedule of Changes in Deferred Revenue (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>9954484 - Disclosure - Divestiture (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/DivestitureDetails</Role>
      <ShortName>Divestiture (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/Divestiture</ParentRole>
      <Position>36</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>9954485 - Disclosure - Debt - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/DebtNarrativeDetails</Role>
      <ShortName>Debt - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>9954486 - Disclosure - Debt - Schedule of Maturities on Debt Outstanding (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/DebtScheduleofMaturitiesonDebtOutstandingDetails</Role>
      <ShortName>Debt - Schedule of Maturities on Debt Outstanding (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>9954487 - Disclosure - Debt - Schedule of Total Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/DebtScheduleofTotalDebtDetails</Role>
      <ShortName>Debt - Schedule of Total Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>9954488 - Disclosure - Software and Other Intangible Assets - Schedule of Carrying Amount and Accumulated Amortization (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssetsScheduleofCarryingAmountandAccumulatedAmortizationDetails</Role>
      <ShortName>Software and Other Intangible Assets - Schedule of Carrying Amount and Accumulated Amortization (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>9954489 - Disclosure - Software and Other Intangible Assets - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssetsNarrativeDetails</Role>
      <ShortName>Software and Other Intangible Assets - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>41</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>9954490 - Disclosure - Software and Other Intangible Assets - Schedule of Estimated Amortization Expense (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SoftwareandOtherIntangibleAssetsScheduleofEstimatedAmortizationExpenseDetails</Role>
      <ShortName>Software and Other Intangible Assets - Schedule of Estimated Amortization Expense (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>42</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>9954491 - Disclosure - Stock-Based Compensation Plans - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansNarrativeDetails</Role>
      <ShortName>Stock-Based Compensation Plans - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>43</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>9954492 - Disclosure - Stock-Based Compensation Plans - Schedule of Stock Option Activity (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansScheduleofStockOptionActivityDetails</Role>
      <ShortName>Stock-Based Compensation Plans - Schedule of Stock Option Activity (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>44</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R45.htm</HtmlFileName>
      <LongName>9954493 - Disclosure - Stock-Based Compensation Plans - Schedule of Nonvested Total Shareholder Return Awards ("TSRs") (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansScheduleofNonvestedTotalShareholderReturnAwardsTSRsDetails</Role>
      <ShortName>Stock-Based Compensation Plans - Schedule of Nonvested Total Shareholder Return Awards ("TSRs") (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>45</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R46.htm</HtmlFileName>
      <LongName>9954494 - Disclosure - Stock-Based Compensation Plans - Schedule of Grant Date Fair Value Weighted Average Assumptions - TSRs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansScheduleofGrantDateFairValueWeightedAverageAssumptionsTSRsDetails</Role>
      <ShortName>Stock-Based Compensation Plans - Schedule of Grant Date Fair Value Weighted Average Assumptions - TSRs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>46</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R47.htm</HtmlFileName>
      <LongName>9954495 - Disclosure - Stock-Based Compensation Plans - Schedule of Nonvested Restricted Share Unit Awards ("RSUs") (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/StockBasedCompensationPlansScheduleofNonvestedRestrictedShareUnitAwardsRSUsDetails</Role>
      <ShortName>Stock-Based Compensation Plans - Schedule of Nonvested Restricted Share Unit Awards ("RSUs") (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>47</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R48.htm</HtmlFileName>
      <LongName>9954496 - Disclosure - Common Stock and Treasury Stock (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CommonStockandTreasuryStockDetails</Role>
      <ShortName>Common Stock and Treasury Stock (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/CommonStockandTreasuryStock</ParentRole>
      <Position>48</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>9954497 - Disclosure - Earnings (Loss) Per Share - Schedule of Reconciliation of Weighted Average Share Amounts Used to Compute both Basic and Diluted Earnings Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/EarningsLossPerShareScheduleofReconciliationofWeightedAverageShareAmountsUsedtoComputebothBasicandDilutedEarningsPerShareDetails</Role>
      <ShortName>Earnings (Loss) Per Share - Schedule of Reconciliation of Weighted Average Share Amounts Used to Compute both Basic and Diluted Earnings Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/EarningsLossPerShareTables</ParentRole>
      <Position>49</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>9954498 - Disclosure - Earnings (Loss) Per Share - Narrative (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/EarningsLossPerShareNarrativeDetails</Role>
      <ShortName>Earnings (Loss) Per Share - Narrative (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/EarningsLossPerShareTables</ParentRole>
      <Position>50</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R51.htm</HtmlFileName>
      <LongName>9954499 - Disclosure - Other, Net (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/OtherNetDetails</Role>
      <ShortName>Other, Net (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/OtherNet</ParentRole>
      <Position>51</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R52.htm</HtmlFileName>
      <LongName>9954500 - Disclosure - Segment Information - Schedule of Reportable Segment (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SegmentInformationScheduleofReportableSegmentDetails</Role>
      <ShortName>Segment Information - Schedule of Reportable Segment (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>52</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R53.htm</HtmlFileName>
      <LongName>9954501 - Disclosure - Segment Information - Schedule of Revenues by Primary Solution Categories, Geographical Location and Long Lived Assets (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/SegmentInformationScheduleofRevenuesbyPrimarySolutionCategoriesGeographicalLocationandLongLivedAssetsDetails</Role>
      <ShortName>Segment Information - Schedule of Revenues by Primary Solution Categories, Geographical Location and Long Lived Assets (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>53</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R54.htm</HtmlFileName>
      <LongName>9954502 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/IncomeTaxes</ParentRole>
      <Position>54</Position>
    </Report>
    <Report instance="aciw-20230930.htm">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>9954503 - Disclosure - Commitments and Contingencies (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.aciworldwide.com/role/CommitmentsandContingenciesDetails</Role>
      <ShortName>Commitments and Contingencies (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.aciworldwide.com/role/CommitmentsandContingencies</ParentRole>
      <Position>55</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" isDefinitelyFs="true" isUsgaap="true" original="aciw-20230930.htm">aciw-20230930.htm</File>
    <File>aciw-20230930.xsd</File>
    <File>aciw-20230930_cal.xml</File>
    <File>aciw-20230930_def.xml</File>
    <File>aciw-20230930_lab.xml</File>
    <File>aciw-20230930_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy items="884">http://fasb.org/us-gaap/2023</BaseTaxonomy>
    <BaseTaxonomy items="30">http://xbrl.sec.gov/dei/2023</BaseTaxonomy>
    <BaseTaxonomy items="4">http://xbrl.sec.gov/ecd/2023</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
