| r0.c0 | HBO [member]/Current | ocw-dm:HBOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r0.c1 | HBO [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:HBOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r1.c0 | MBO [member]/Current | ocw-dm:MBOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r1.c1 | MBO [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:MBOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r2.c0 | VO [member]/Current | ocw-dm:VOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r2.c1 | VO [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:VOMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r3.c0 | PO [member]/Current | ocw-dm:POMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r3.c1 | PO [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:POMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r4.c0 | Other government funded activities [member]/Current | ocw-dm:OtherGovernmentFundedActivitiesMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r4.c1 | Other government funded activities [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:OtherGovernmentFundedActivitiesMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r5.c0 | Segment reporting, total [member]/Current | ocw-dm:SegmentReportingTotalMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r5.c1 | Segment reporting, total [member]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-dm:SegmentReportingTotalMember | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r6.c0 | Segment information, classes [title]/Current | ocw-abstr:SegmentReportingClassesTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r6.c1 | Segment information, classes [title]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-abstr:SegmentReportingClassesTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r7.c0 | Central government contributions/Current | ocw-i:GovernmentContributionsCentralGovernment | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r7.c1 | Central government contributions/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:GovernmentContributionsCentralGovernment | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r8.c0 | Government contributions and subsidies overige overheden/Current | ocw-i:GovernmentContributionsSubsidiesOtherGovernments | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r8.c1 | Government contributions and subsidies overige overheden/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:GovernmentContributionsSubsidiesOtherGovernments | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r9.c0 | Tuition and exam fees/Current | ocw-i:IncomeTuitionAndExamFees | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r9.c1 | Tuition and exam fees/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:IncomeTuitionAndExamFees | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r10.c0 | Income from third party contracts/Current | ocw-i:IncomeThirdPartyContracts | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r10.c1 | Income from third party contracts/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:IncomeThirdPartyContracts | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r11.c0 | Other operating income/Current | jenv-bw2-i:OperatingIncomeOther | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r11.c1 | Other operating income/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:OperatingIncomeOther | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r12.c0 | Operating income/Current | jenv-bw2-i:OperatingIncome | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r12.c1 | Operating income/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:OperatingIncome | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r13.c0 | Income/Current | jenv-bw2-abstr:BW2IncomeTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r13.c1 | Income/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-abstr:BW2IncomeTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r14.c0 | Expenses of employee benefits/Current | jenv-bw2-i:EmployeeBenefitsExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r14.c1 | Expenses of employee benefits/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:EmployeeBenefitsExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r15.c0 | Amortisation of intangible assets and depreciation of property, plant and equipment/Current | jenv-bw2-i:DepreciationPropertyPlantEquipmentAmortisationIntangibleAssets | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r15.c1 | Amortisation of intangible assets and depreciation of property, plant and equipment/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:DepreciationPropertyPlantEquipmentAmortisationIntangibleAssets | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r16.c0 | Accommodation costs/Current | rj-i:AccommodationCosts | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r16.c1 | Accommodation costs/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | rj-i:AccommodationCosts | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r17.c0 | Other operating expenses/Current | jenv-bw2-i:OperatingExpensesOther | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r17.c1 | Other operating expenses/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:OperatingExpensesOther | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r18.c0 | Income transfers of government contributions to school boards/Current | ocw-i:GovernmentContributionsIncomeTransfersSchoolBoards | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r18.c1 | Income transfers of government contributions to school boards/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:GovernmentContributionsIncomeTransfersSchoolBoards | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r19.c0 | Operating expenses/Current | jenv-bw2-i:OperatingExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r19.c1 | Operating expenses/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:OperatingExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r20.c0 | Expenses/Current | jenv-bw2-abstr:BW2ExpensesTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r20.c1 | Expenses/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-abstr:BW2ExpensesTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r21.c0 | Operating result/Current | jenv-bw2-i:OperatingResult | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r21.c1 | Operating result/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:OperatingResult | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r22.c0 | Revaluation reserve realised/Current | ocw-i:RevaluationReserveRealised | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r22.c1 | Revaluation reserve realised/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:RevaluationReserveRealised | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r23.c0 | Financial income/Current | rj-i:FinancialIncome | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r23.c1 | Financial income/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | rj-i:FinancialIncome | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r24.c0 | Financial expenses/Current | rj-i:FinancialExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r24.c1 | Financial expenses/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | rj-i:FinancialExpenses | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r25.c0 | Result before tax/Current | jenv-bw2-i:ResultBeforeTax | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r25.c1 | Result before tax/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:ResultBeforeTax | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r26.c0 | Income tax expense/Current | jenv-bw2-i:IncomeTaxExpense | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r26.c1 | Income tax expense/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:IncomeTaxExpense | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r27.c0 | Share in results of participating interests/Current | jenv-bw2-i:ShareInResultsParticipatingInterests | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r27.c1 | Share in results of participating interests/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:ShareInResultsParticipatingInterests | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r28.c0 | Result after tax/Current | jenv-bw2-i:ResultAfterTax | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r28.c1 | Result after tax/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:ResultAfterTax | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r29.c0 | Profit (loss) attributable to non-controlling interest not accrued to legal entity/Current | jenv-bw2-i:ResultAttributableNoncontrollingInterest | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r29.c1 | Profit (loss) attributable to non-controlling interest not accrued to legal entity/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | jenv-bw2-i:ResultAttributableNoncontrollingInterest | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r30.c0 | Sum of results/Current | ocw-i:SumOfResults | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r30.c1 | Sum of results/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-i:SumOfResults | nl-types:monetaryNoDecimals20ItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r31.c0 | Segment reporting, income statement, line items [title]/Current | ocw-abstr:IncomeStatementSegmentReportingLineItemsTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |
| r31.c1 | Segment reporting, income statement, line items [title]/ocw-table_IncomeStatementSegmentReporting-x.1.1.1.1 | ocw-abstr:IncomeStatementSegmentReportingLineItemsTitle | xbrli:stringItemType | duration | jenv-bw2-dm:SeparateMember | ocw-dm:ActualsMember | xs:date('2020-01-01')/xs:date('2020-12-31') |