Investments, Forward Contracts and Fair Value Measurements - Gross Unrealized Losses on Available-For-Sale Securities (Details) - USD ($) $ in Millions	Jun. 29, 2019	Jun. 30, 2018
Available-For-Sale Investments
Less than 12 Months	$ 0.0	$ (0.6)
Greater than 12 Months	(0.3)	(0.6)
Total	(0.3)	(1.2)
U.S. treasuries and agencies
Available-For-Sale Investments
Less than 12 Months		(0.1)
Greater than 12 Months		(0.1)
Total		(0.2)
Asset-backed securities
Available-For-Sale Investments
Less than 12 Months	0.0	(0.1)
Greater than 12 Months	(0.3)	(0.3)
Total	$ (0.3)	(0.4)
Corporate securities
Available-For-Sale Investments
Less than 12 Months		(0.4)
Greater than 12 Months		(0.2)
Total		$ (0.6)

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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