Acquisition Effect of the change in Starbucks ownership interest in Starbucks Japan on Starbucks equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 29, 2015	Mar. 30, 2014	Mar. 29, 2015	Mar. 30, 2014
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Net earnings attributable to Starbucks	$ 494.9	$ 427.0	$ 1,478.3	$ 967.6
Change from net earnings attributable to Starbucks and transfers (to)/from noncontrolling interest			1,480.0	967.6
Additional Paid-in Capital [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Increase/(decrease) in additional paid-in capital for purchase of interest in subsidiary			$ 1.7	$ 0