Investments and Fair Value Measurements (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Apr. 02, 2016	Mar. 28, 2015	Apr. 02, 2016	Mar. 28, 2015	Jun. 27, 2015
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	$ 423.5		$ 423.5		$ 496.6
Gross Unrealized Gains	165.7		165.7		0.1
Gross Unrealized Losses	(0.5)		(0.5)		(0.3)
Fair Value	588.7		$ 588.7		496.4
Term of maturities of securities classified as current assets included in short-term investments			12 months
Other-than-temporary impairment loss	0.0	$ 0.0	$ 0.0	$ 0.0
Cash equivalents
Available-For-Sale Investments
Fair Value	34.7		34.7		33.7
Short-term investments
Available-For-Sale Investments
Fair Value	309.1		309.1		461.9
Other non-current assets
Available-For-Sale Investments
Fair Value	0.6		0.6		0.8
Debt securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	344.7		344.7
Gross Unrealized Gains	0.2		0.2
Gross Unrealized Losses	(0.5)		(0.5)
Fair Value	344.4		344.4
Contractual maturities of debt securities classified as available-for-sale securities, Amortized Cost/Carrying Cost
Amortized cost of amounts maturing in less than 1 year	251.6		251.6
Amortized cost of amounts maturing in 1-5 years	91.4		91.4
Amortized cost of amounts maturing in more than 5 years	1.7		1.7
Total amortized cost of debt available-for-sale securities	344.7		344.7
Contractual maturities of the debt securities classified as available-for-sale securities, Estimated Fair Value
Estimated fair value amounts maturing in less than 1 year	251.6		251.6
Estimated fair value amounts maturing in 1 -5 years	91.4		91.4
Estimated fair value amounts maturing in more than 5 years	1.4		1.4
Total estimated fair value of debt available-for-sale securities	344.4		344.4
U.S. treasuries
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	60.2		60.2		51.9
Gross Unrealized Gains	0.0		0.0		0.0
Gross Unrealized Losses	0.0		0.0		0.0
Fair Value	60.2		60.2		51.9
U.S. agencies
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	29.1		29.1		96.0
Gross Unrealized Gains	0.0		0.0		0.0
Gross Unrealized Losses	0.0		0.0		0.0
Fair Value	29.1		29.1		96.0
Municipal bonds and sovereign debt instruments
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	2.3		2.3		4.0
Gross Unrealized Gains	0.0		0.0		0.0
Gross Unrealized Losses	0.0		0.0		0.0
Fair Value	2.3		2.3		4.0
Asset-backed securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	46.3		46.3		70.6
Gross Unrealized Gains	0.1		0.1		0.0
Gross Unrealized Losses	(0.4)		(0.4)		(0.2)
Fair Value	46.0		46.0		70.4
Corporate securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	206.8		206.8		274.1
Gross Unrealized Gains	0.1		0.1		0.1
Gross Unrealized Losses	(0.1)		(0.1)		(0.1)
Fair Value	206.8		206.8		$ 274.1
Marketable equity securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	78.8		78.8
Gross Unrealized Gains	165.5		165.5
Gross Unrealized Losses	0.0		0.0
Fair Value	$ 244.3		244.3
Number of shares sold (in shares)	2.5
Realized gain on sale of marketable equity securities	$ 39.7
Income tax effect related to gain on sale of marketable securitiy	1.0
Marketable equity securities | Short-term investments
Available-For-Sale Investments
Fair Value	$ 244.3		$ 244.3