v3.19.2

Contractual Commitments, Contingencies, and Off-Balance Sheet Arrangements - Data Center Agreements - Total Expenses (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2017
Loss Contingencies [Line Items] |  |  |
Total expenses | $ 106.1 | $ 107.5 | $ 104.8
IT Services Agreement |  |  |
Loss Contingencies [Line Items] |  |  |
Total expenses | 100.0 | 101.2 | 99.3
EU IT Services Agreement |  |  |
Loss Contingencies [Line Items] |  |  |
Total expenses | $ 6.1 | $ 6.3 | $ 5.5

X
- Definition Total expenses on agreements. + References No definition available. + Details
Name: | br_TotalExpensesOnAgreements
Namespace Prefix: | br_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=br_InformationTechnologyServicesAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=br_EUInformationTechnologyServicesAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |