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Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 30, 2017	Dec. 31, 2016	Aug. 21, 2013
Numerator:
Net income (loss)	$ (3.7)	$ 49.2	$ (8.5)	$ 127.2
Weighted-average number of common shares outstanding
Basic (in shares)	227.4	230.5	227.7	231.4
Effect of dilutive securities from stock-based benefit plans (in shares)	0.0	3.7	0.0	4.4
Diluted (in shares)	227.4	234.2	227.7	235.8
Net (loss) income per share:
Basic (in dollars per share)	$ (0.02)	$ 0.21	$ (0.04)	$ 0.55
Diluted (in dollars per share)	$ (0.02)	$ 0.21	$ (0.04)	$ 0.54
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	9.3	1.7	9.4	1.6
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	1.5	1.6	1.6
Restricted Stock Units
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	7.7	0.2	7.8	0.0