Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Available-for-sale Securities [Abstract]
Proceeds from sale of available-for-sale securities	$ 1,454.8	$ 60.2	$ 0
Trading Securities [Abstract]
Management Deferred Compensation Plan liability	106.4	101.6
Trading securities, change in net unrealized holding gain (loss)	$ 1.2	$ 11.7	$ 10.9
Maximum [Member]
Available-for-sale Securities [Abstract]
Long-term investments, contractual maturity period	7 years
Auction Rate Securities [Member] | Minimum [Member]
Available-for-sale Securities [Abstract]
Long-term investments, contractual maturity period	16 years
Auction Rate Securities [Member] | Maximum [Member]
Available-for-sale Securities [Abstract]
Long-term investments, contractual maturity period	29 years