Investments, Forward Contracts and Fair Value Measurements - Amortized Cost to Fair Value Reconciliation (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jul. 02, 2016
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	$ 493.1	$ 410.0
Gross Unrealized Gains	50.0	109.5
Gross Unrealized Losses	(0.9)	(0.4)
Fair Value	542.2	519.1
Debt securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	478.8	347.9
Gross Unrealized Gains	0.0	0.3
Gross Unrealized Losses	(0.9)	(0.4)
Fair Value	477.9	347.8
U.S. treasuries
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	67.6	46.1
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	(0.1)	0.0
Fair Value	67.5	46.1
U.S. agencies
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	36.5	24.9
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	(0.1)	0.0
Fair Value	36.4	24.9
Municipal bonds and sovereign debt instruments
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	3.5	2.0
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Fair Value	3.5	2.0
Asset-backed securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	62.9	50.4
Gross Unrealized Gains	0.0	0.1
Gross Unrealized Losses	(0.3)	(0.3)
Fair Value	62.6	50.2
Corporate securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	302.3	224.5
Gross Unrealized Gains	0.0	0.2
Gross Unrealized Losses	(0.4)	(0.1)
Fair Value	301.9	224.6
Certificates of deposits
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	6.0
Gross Unrealized Gains	0.0
Gross Unrealized Losses	0.0
Fair Value	6.0
Marketable equity securities
Available-For-Sale Investments
Amortized Cost/ Carrying Cost	14.3	62.1
Gross Unrealized Gains	50.0	109.2
Gross Unrealized Losses	0.0	0.0
Fair Value	$ 64.3	$ 171.3

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
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-Section 50
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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-Publisher FASB
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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

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