CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (4.8)	$ 78.0
Other comprehensive income:
Net change in cumulative translation adjustment, net of tax	10.2	3.4
Net change in available-for-sale investments, net of tax:
Unrealized holding gain arising during period	0.0	84.4
Less: reclassification adjustments included in net (loss) income	0.0	(81.5)
Net change in defined benefit obligation, net of tax:
Amortization of actuarial losses	0.4	0.5
Net change in accumulated other comprehensive loss	10.6	6.8
Comprehensive income	$ 5.8	$ 84.8