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Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	May 29, 2018	Aug. 21, 2013
Numerator:
Net loss	$ (15.3)	$ (7.6)
Weighted-average number of common shares outstanding
Basic (in shares)	227.2	228.1
Effect of dilutive securities from stock-based benefit plans (in shares)	0.0	0.0
Diluted (in shares)	227.2	228.1
Net loss per share:
Basic (in dollars per share)	$ (0.07)	$ (0.03)
Diluted (in dollars per share)	$ (0.07)	$ (0.03)
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	8.6	9.7
2033 Notes \| Convertible Notes
Convertible notes
Interest rate on senior convertible notes	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%
Conversion price of debt (in dollars per share)	$ 13.22
2023 Notes \| Convertible Notes
Convertible notes
Interest rate on senior convertible notes	1.75%		1.75%
Conversion price of debt (in dollars per share)	$ 13.94
Stock options and ESPP
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	1.6	1.7
Restricted Stock Units
Anti-dilutive securities excluded from computation of earnings per share
Total potentially dilutive securities (in shares)	7.0	8.0