v3.19.2

Employee Benefit Plans - Other Post-retirement Benefit Plan (Details) - Executive Retiree Health Insurance Plan - USD ($) $ in Millions | 12 Months Ended
--- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, maximum age eligibility | 65 years |  |
Benefit expense | $ 0.5 | $ 0.4 | $ 0.3
Benefit obligation | $ 5.2 | $ 5.3 | $ 4.9

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- Definition Defined Benefit Plan, Age Eligibility, Maximum + References No definition available. + Details
Name: | br_DefinedBenefitPlanAgeEligibilityMaximum
Namespace Prefix: | br_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- Definition Other Postretirement Plan, Benefit Obligation + References No definition available. + Details
Name: | br_OtherPostretirementPlanBenefitObligation
Namespace Prefix: | br_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Amount of cost (reversal of cost) for other postretirement benefits. Excludes pension benefits. + References No definition available. + Details
Name: | us-gaap_OtherPostretirementBenefitExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_DefinedBenefitPostretirementHealthCoverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |