v3.19.2

Employee Benefit Plans - Other Post-employment Benefit Obligations (Details) - The Gratuity Plan - USD ($) $ in Millions | 12 Months Ended
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Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Benefit expense | $ 1.3 | $ 1.0 | $ 1.3
Benefit obligation | $ 5.8 | $ 5.0 | $ 4.1

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- Definition Other Postemployment Plan, Benefit Obligation + References No definition available. + Details
Name: | br_OtherPostemploymentPlanBenefitObligation
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
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Period expense related to postemployment benefits. + References No definition available. + Details
Name: | us-gaap_PostemploymentBenefitsPeriodExpense
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_PostemploymentRetirementBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |