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								12 Months Ended
	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Jan. 01, 2017	Oct. 02, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 27, 2015	Oct. 01, 2017	Oct. 02, 2016	Sep. 27, 2015
Earnings Per Share [Abstract]
Net earnings attributable to Starbucks	$ 788.5	$ 691.6	$ 652.8	$ 751.8	$ 801.0	$ 754.1	$ 575.1	$ 687.6	$ 2,884.7	$ 2,817.7	$ 2,757.4
Weighted average common shares and common stock units outstanding (for basic calculation)									1,449.5	1,471.6	1,495.9
Dilutive effect of outstanding common stock options and RSUs									12.0	15.1	17.5
Weighted average common and common equivalent shares outstanding (for diluted calculation)									1,461.5	1,486.7	1,513.4
EPS - basic									$ 1.99	$ 1.91	$ 1.84
EPS - diluted	$ 0.54	$ 0.47	$ 0.45	$ 0.51	$ 0.54	$ 0.51	$ 0.39	$ 0.46	$ 1.97	$ 1.90	$ 1.82