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Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Aug. 21, 2013
Numerator:
Net (loss) income	$ (8.7)	$ 26.0	$ (17.2)	$ 153.2
Weighted-average number of common shares outstanding
Basic (in shares)	226.3	229.4	227.3	230.8
Effect of dilutive securities from stock-based benefit plans (in shares)	0.0	5.2	0.0	5.1
Diluted (in shares)	226.3	234.6	227.3	235.9
Net (loss) income per share:
Basic (in dollars per share)	$ (0.04)	$ 0.11	$ (0.08)	$ 0.66
Diluted (in dollars per share)	$ (0.04)	$ 0.11	$ (0.08)	$ 0.65
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	8.4	0.3	9.1	0.3
2033 Notes \| Convertible Notes
Convertible notes
Interest rate on senior convertible notes	0.625%		0.625%		0.625%
Conversion price of debt (in dollars per share)			$ 11.28
2024 Notes \| Convertible Notes
Convertible notes
Interest rate on senior convertible notes	1.00%		1.00%
Conversion price of debt (in dollars per share)			$ 13.22
Stock options and ESPP
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	1.6	0.3	1.6	0.3
Restricted Stock Units
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	6.8	0.0	7.5	0.0