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Business Acquisitions - Summary of Changes to Goodwill Balance (Detail) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2019 | Jun. 30, 2018
Goodwill [Line Items] |  |  |  |  |
Beginning balance |  | $ 318.6 | [1] | $ 316.1 |
Working capital adjustment |  | 4.4 |  | 1.9 |
Ending balance | $ 417.2 | 417.2 |  | $ 318.6 | [1]
Counsyl Inc [Member] |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |
Beginning balance | 94.9 |  |  |  |
Fair value adjustment to equipment | 0.7 | 0.7 |  |  |
Intangible adjustment | 2.9 | 2.9 |  |  |
Working capital adjustment | (1.1) | (1.1) |  |  |
Change in deferred tax liability | 1.9 | 1.9 |  |  |
Ending balance | $ 99.3 | $ 99.3 |  |  |
[1] | Amounts adjusted due to the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606). See Note 1 to the financial statements of this report for additional information.

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