Investments - Available for Sale Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 28, 2014	Jun. 27, 2015
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 20.7
Net unrealized investment gains (losses):
Equity securities, at cost less impairments	17.1	$ 17.1
Gross unrealized gains	3.8	5.7
Gross unrealized losses	(0.2)	(10.1)
Estimated fair value of equity securities	20.7	12.7
Available-for-sale Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	5.9	$ 12.7
Available-for-sale Securities, Gross Realized Losses	(9.9)
Other Noncurrent Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 14.8