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Business Acquisitions - Summary of Changes to Goodwill Balance (Detail) - USD ($) $ in Millions	10 Months Ended	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017
Goodwill [Line Items]
Beginning balance		$ 316.1	$ 195.3
Working capital adjustment		1.9	3.6
Ending balance	$ 318.6	318.6	$ 316.1
Assurex [Member]
Goodwill [Line Items]
Beginning balance	119.2
Fair value adjustment to equipment and intangibles	(0.1)	(0.1)
Working capital adjustment	0.2	0.2
Change in deferred tax liability	1.8	1.8
Ending balance	$ 121.1	$ 121.1

X

- Definition

Goodwill adjustment to deferred tax assets liabilities.

+ References

No definition available.

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
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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.

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- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
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- Definition

Amount of transfers into (out of) an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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