Investments and Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 28, 2013	Jun. 29, 2013
Maximum
Foreign Currency Forward Contracts
Foreign currency forward contracts, expiration period	120 days	120 days
Level 3
Fair Value Measurements
Total assets	$ 0	$ 0
Recurring basis | Cash and cash equivalents
Fair Value Measurements
Total assets	374.3
Recurring basis | Short-term investments
Fair Value Measurements
Total assets	607.8
Recurring basis | Restricted cash
Fair Value Measurements
Total assets	29.7
Recurring basis | Other non-current assets
Fair Value Measurements
Total assets	4.8
Recurring basis | Total fair value
Fair Value Measurements
Total debt available-for-sale securities	687.7
Money market funds	324.4
Trading securities	4.5
Total assets	1,016.6
Recurring basis | Total fair value | U.S. treasuries
Fair Value Measurements
Total debt available-for-sale securities	50.5
Recurring basis | Total fair value | U.S. agencies
Fair Value Measurements
Total debt available-for-sale securities	119.4
Recurring basis | Total fair value | Municipal bonds and sovereign debt instruments
Fair Value Measurements
Total debt available-for-sale securities	20.9
Recurring basis | Total fair value | Asset-backed securities
Fair Value Measurements
Total debt available-for-sale securities	40.6
Recurring basis | Total fair value | Corporate securities
Fair Value Measurements
Total debt available-for-sale securities	456.3
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Measurements
Total debt available-for-sale securities	50.5
Money market funds	324.4
Trading securities	4.5
Total assets	379.4
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. treasuries
Fair Value Measurements
Total debt available-for-sale securities	50.5
Recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Total debt available-for-sale securities	637.2
Total assets	637.2
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. agencies
Fair Value Measurements
Total debt available-for-sale securities	119.4
Recurring basis | Significant Other Observable Inputs (Level 2) | Municipal bonds and sovereign debt instruments
Fair Value Measurements
Total debt available-for-sale securities	20.9
Recurring basis | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Fair Value Measurements
Total debt available-for-sale securities	40.6
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate securities
Fair Value Measurements
Total debt available-for-sale securities	$ 456.3