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Income Taxes - Summary of Domestic and Foreign Components of (Loss) Before Provision for Income Taxes and the Provision for Income Taxes (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2019
Income Tax Disclosure [Line Items] |  |  |
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest | $ (164.3) | $ (124.6) | $ (126.2)
Current: |  |  |
Current Income Tax Expense (Benefit) | 12.1 | 10.5 | 12.6
Deferred: |  |  |
Deferred Income Tax Expense (Benefit) | (18.0) | (16.0) | (16.8)
Total benefit from income taxes | (5.9) | (5.5) | (4.2)
United Kingdom |  |  |
Income Tax Disclosure [Line Items] |  |  |
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest | (125.3) | (118.2) | (96.3)
Current: |  |  |
Current Income Tax Expense (Benefit) | 0.3 | 0.6 | 1.1
Deferred: |  |  |
Deferred Income Tax Expense (Benefit) | 0.0 | (0.4) | (0.3)
United States |  |  |
Income Tax Disclosure [Line Items] |  |  |
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest | (53.8) | (24.5) | (42.0)
Current: |  |  |
Current Income Tax Expense (Benefit) | 2.4 | (6.2) | 1.9
Deferred: |  |  |
Deferred Income Tax Expense (Benefit) | (15.5) | 1.3 | (7.2)
Other foreign |  |  |
Income Tax Disclosure [Line Items] |  |  |
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest | 14.8 | 18.1 | 12.1
Current: |  |  |
Current Income Tax Expense (Benefit) | 9.4 | 16.1 | 9.6
Deferred: |  |  |
Deferred Income Tax Expense (Benefit) | $ (2.5) | $ (16.9) | $ (9.3)

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