Acquired Intangibles and Goodwill - Summary of Life, Gross Carrying Value and Related Accumulated Amortization of Acquired Intangible Assets (Detail) - USD ($) $ in Millions	9 Months Ended
Mar. 31, 2018	Jun. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 424.3	$ 282.0
Accumulated amortization	(214.9)	(181.0)
Acquired intangibles, net	$ 209.4	101.0
Weighted Average Life in Years	4 years 7 months 6 days
Display Driver Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 164.0	164.0
Weighted Average Life in Years	5 years 3 months 18 days
Audio and Video Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 118.2
Weighted Average Life in Years	4 years 8 months 12 days
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 66.2	48.4
Weighted Average Life in Years	3 years 7 months 6 days
Fingerprint Authentication Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 55.7	63.5
Weighted Average Life in Years	4 years
Licensed Technology and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 9.0	1.3
Weighted Average Life in Years	4 years 3 months 19 days
Tradename [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 1.7
Weighted Average Life in Years	7 years
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 4.6	$ 4.8
Weighted Average Life in Years	7 years 8 months 12 days
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 1.3
Weighted Average Life in Years	6 months
In-Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangibles, gross	$ 3.6

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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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.

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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