CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 30, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 204.8	$ 11.8	$ 211.9	$ 8.4
Other comprehensive income (loss):
Net change in cumulative translation adjustment, net of tax	0.1	(3.7)	2.0	(4.6)
Net change in unrealized loss on available-for-sale securities, net of tax	(0.6)	0.0	(0.7)	0.0
Net change in accumulated other comprehensive income (loss)	(0.5)	(3.7)	1.3	(4.6)
Comprehensive income	$ 204.3	$ 8.1	$ 213.2	$ 3.8