Earnings Per Share (Calculation of Net Earnings Per Common Share (EPS) - Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2016	Mar. 29, 2015	Mar. 27, 2016	Mar. 29, 2015
Earnings Per Share [Abstract]
Net earnings attributable to Starbucks	$ 575.1	$ 494.9	$ 1,262.6	$ 1,478.3
Weighted average common shares outstanding (for basic calculation)	1,472.1	1,500.5	1,479.0	1,499.7
Dilutive effect of outstanding common stock options and RSUs	14.5	16.0	16.0	17.0
Weighted average common and common equivalent shares outstanding (for diluted calculation)	1,486.6	1,516.5	1,495.0	1,516.7
EPS - basic	$ 0.39	$ 0.33	$ 0.85	$ 0.99
EPS - diluted	$ 0.39	$ 0.33	$ 0.84	$ 0.97