<?xml version='1.0' encoding='utf-8'?>
<FilingSummary>
  <Version>3.20.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>51</ContextCount>
  <ElementCount>243</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>17</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>4</UnitCount>
  <MyReports>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>00000001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>00000002 - Statement - CONSOLIDATED BALANCE SHEETS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>00000003 - Statement - CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>00000004 - Statement - CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConsolidatedStatementOfOperations</Role>
      <ShortName>CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>00000005 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' DEFICIT (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConsolidatedStatementsOfChangesInStockholdersDeficit</Role>
      <ShortName>CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' DEFICIT (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>00000006 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConsolidatedStatementOfCashFlows</Role>
      <ShortName>CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>00000007 - Disclosure - ORGANIZATION AND DESCRIPTION OF BUSINESS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/OrganizationAndDescriptionOfBusiness</Role>
      <ShortName>ORGANIZATION AND DESCRIPTION OF BUSINESS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>00000008 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/SummaryOfSignificantAccountingPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>00000009 - Disclosure - GOING CONCERN</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/GoingConcern</Role>
      <ShortName>GOING CONCERN</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>00000010 - Disclosure - RELATED PARTY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/RelatedParty</Role>
      <ShortName>RELATED PARTY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>00000011 - Disclosure - CONVERTIBLE DEBT - RELATED PARTY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebt-RelatedParty</Role>
      <ShortName>CONVERTIBLE DEBT - RELATED PARTY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>00000012 - Disclosure - NOTES PAYABLE</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://greycloaktech.com/role/NotesPayable</Role>
      <ShortName>NOTES PAYABLE</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>00000013 - Disclosure - CONVERTIBLE DEBT</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebt</Role>
      <ShortName>CONVERTIBLE DEBT</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>00000014 - Disclosure - STOCKHOLDERS' EQUITY</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/StockholdersEquity</Role>
      <ShortName>STOCKHOLDERS' EQUITY</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>00000015 - Disclosure - ACQUISITIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/Acquisitions</Role>
      <ShortName>ACQUISITIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>00000016 - Disclosure - DISCONTINUED OPERATIONS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/DiscontinuedOperations</Role>
      <ShortName>DISCONTINUED OPERATIONS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>00000017 - Disclosure - BUSINESS SEGMENT INFORMATION</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/BusinessSegmentInformation</Role>
      <ShortName>BUSINESS SEGMENT INFORMATION</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>17</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>00000018 - Disclosure - SUBSEQUENT EVENTS</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/SubsequentEvents</Role>
      <ShortName>SUBSEQUENT EVENTS</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>18</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>00000019 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/SummaryOfSignificantAccountingPoliciesPolicies</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <Position>19</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>00000020 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/SummaryOfSignificantAccountingPoliciesTables</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/SummaryOfSignificantAccountingPolicies</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>00000021 - Disclosure - CONVERTIBLE DEBT - RELATED PARTY (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebt-RelatedPartyTables</Role>
      <ShortName>CONVERTIBLE DEBT - RELATED PARTY (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/ConvertibleDebt-RelatedParty</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>00000022 - Disclosure - NOTES PAYABLE (Tables)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://greycloaktech.com/role/NotesPayableTables</Role>
      <ShortName>NOTES PAYABLE (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/NotesPayable</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>00000023 - Disclosure - CONVERTIBLE DEBT (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebtTables</Role>
      <ShortName>CONVERTIBLE DEBT (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/ConvertibleDebt-RelatedParty</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>00000024 - Disclosure - ACQUISITIONS (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/AcquisitionsTables</Role>
      <ShortName>ACQUISITIONS (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/Acquisitions</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>00000025 - Disclosure - BUSINESS SEGMENT INFORMATIONITION (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/BusinessSegmentInformationitionTables</Role>
      <ShortName>BUSINESS SEGMENT INFORMATIONITION (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/BusinessSegmentInformation</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>00000026 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/SummaryOfSignificantAccountingPoliciesDetails</Role>
      <ShortName>SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/SummaryOfSignificantAccountingPoliciesTables</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>00000027 - Disclosure - GOING CONCERN (Details Narrative)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/GoingConcernDetailsNarrative</Role>
      <ShortName>GOING CONCERN (Details Narrative)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/GoingConcern</ParentRole>
      <Position>27</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>00000028 - Disclosure - RELATED PARTY (Details Narrative)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/RelatedPartyDetailsNarrative</Role>
      <ShortName>RELATED PARTY (Details Narrative)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/RelatedParty</ParentRole>
      <Position>28</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>00000029 - Disclosure - CONVERTIBLE DEBT - RELATED PARTY (Details Narrative)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebt-RelatedPartyDetailsNarrative</Role>
      <ShortName>CONVERTIBLE DEBT - RELATED PARTY (Details Narrative)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/ConvertibleDebt-RelatedPartyTables</ParentRole>
      <Position>29</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>00000030 - Disclosure - NOTES PAYABLE (Details Narrative)</LongName>
      <ReportType>Notes</ReportType>
      <Role>http://greycloaktech.com/role/NotesPayableDetailsNarrative</Role>
      <ShortName>NOTES PAYABLE (Details Narrative)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/NotesPayableTables</ParentRole>
      <Position>30</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>00000031 - Disclosure - CONVERTIBLE DEBT (Details Narrative)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/ConvertibleDebtDetailsNarrative</Role>
      <ShortName>CONVERTIBLE DEBT (Details Narrative)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/ConvertibleDebt-RelatedPartyTables</ParentRole>
      <Position>31</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>00000032 - Disclosure - ACQUISITIONS (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/AcquisitionsDetails</Role>
      <ShortName>ACQUISITIONS (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/AcquisitionsTables</ParentRole>
      <Position>32</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>00000033 - Disclosure - ACQUISITIONS (Details 1)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/AcquisitionsDetails1</Role>
      <ShortName>ACQUISITIONS (Details 1)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/AcquisitionsTables</ParentRole>
      <Position>33</Position>
    </Report>
    <Report instance="grck-20190630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>00000034 - Disclosure - BUSINESS SEGMENT INFORMATION (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://greycloaktech.com/role/BusinessSegmentInformationDetails</Role>
      <ShortName>BUSINESS SEGMENT INFORMATION (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://greycloaktech.com/role/BusinessSegmentInformationitionTables</ParentRole>
      <Position>34</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>grck-20190630.xml</File>
    <File>grck-20190630.xsd</File>
    <File>grck-20190630_cal.xml</File>
    <File>grck-20190630_def.xml</File>
    <File>grck-20190630_lab.xml</File>
    <File>grck-20190630_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies>
    <BaseTaxonomy>http://fasb.org/us-gaap/2019-01-31</BaseTaxonomy>
    <BaseTaxonomy>http://xbrl.sec.gov/dei/2019-01-31</BaseTaxonomy>
  </BaseTaxonomies>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
