Accumulated Other Comprehensive (Loss) Income (Details) $ in Millions	3 Months Ended
	Oct. 03, 2015 USD ($)
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ (48.0)
Transfer to Lumentum	(7.8)
Other comprehensive (loss) income before reclassification	71.7
Amounts reclassified from accumulated other comprehensive income (loss)	0.2
Net current-period other comprehensive (loss) income	71.9
Balance at the end of the period	16.1
Tax impact of amortization of actuarial losses	0.0
Marketable equity investments | Lumentum
Changes in accumulated other comprehensive income (loss) by component
Unrealized gain on marketable equity securities	84.0
Income tax expense impact from unrealized holding gains on marketable equity securities	2.4
Unrealized gains (losses) on available-for-sale investments
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(3.2)
Transfer to Lumentum	0.0
Other comprehensive (loss) income before reclassification	81.7
Amounts reclassified from accumulated other comprehensive income (loss)	0.0
Net current-period other comprehensive (loss) income	81.7
Balance at the end of the period	78.5
Foreign currency translation adjustments
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(29.2)
Transfer to Lumentum	(8.9)
Other comprehensive (loss) income before reclassification	(10.0)
Amounts reclassified from accumulated other comprehensive income (loss)	0.0
Net current-period other comprehensive (loss) income	(10.0)
Balance at the end of the period	(48.1)
Defined benefit obligation, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(15.6)
Transfer to Lumentum	1.1
Other comprehensive (loss) income before reclassification	0.0
Amounts reclassified from accumulated other comprehensive income (loss)	0.2
Net current-period other comprehensive (loss) income	0.2
Balance at the end of the period	$ (14.3)