Selected Quarterly Financial Information (Schedule of Selected Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ 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
Selected Quarterly Financial Information [Abstract]
Total net revenues	$ 5,698.3	$ 5,661.5	$ 5,294.0	$ 5,732.9	$ 5,711.2	$ 5,238.0	$ 4,993.2	$ 5,373.5	$ 22,386.8	$ 21,315.9	$ 19,162.7
Operating income	1,022.5	1,044.2	935.4	1,132.6	1,227.5	1,022.3	864.2	1,058.0	4,134.7	4,171.9	3,601.0
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
EPS - diluted	$ 0.54	$ 0.47	$ 0.45	$ 0.51	$ 0.54	$ 0.51	$ 0.39	$ 0.46	$ 1.97	$ 1.90	$ 1.82