Equity (Impact of Reclassifications from Accumulated Other Comprehensive Income on Earnings (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 02, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 28, 2014	Oct. 02, 2016	Sep. 27, 2015	Sep. 28, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net									$ 108.0	$ 43.0	$ 142.7
Amounts Reclassified from AOCI, Interest expense									(81.3)	(70.5)	(64.1)
Amounts Reclassified from AOCI, Revenue	$ 5,711.2	$ 5,238.0	$ 4,993.2	$ 5,373.5	$ 4,914.8	$ 4,881.2	$ 4,563.5	$ 4,803.2	21,315.9	19,162.7	16,447.8
Amounts Reclassified from AOCI, Cost of sales including occupancy costs									(8,511.1)	(7,787.5)	(6,858.8)
Gain resulting from acquisition of joint venture									0.0	390.6	0.0
Amounts Reclassified from AOCI, Tax (expense)/benefit									(1,379.7)	(1,143.7)	$ (1,092.0)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified, from AOCI, Total before tax									(78.2)	65.9
Amounts Reclassified from AOCI, Tax (expense)/benefit									11.8	(23.5)
Amounts Reclassified from AOCI, Net of tax									(66.4)	42.4
Available-for-sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax									(1.0)	(0.6)
Available-for-sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net									1.6	1.0
Net Investment Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax									0.0	(4.6)
Net Investment Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain resulting from acquisition of joint venture									0.0	7.2
Translation Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax									0.0	14.3
Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net									0.0	(7.1)
Gain resulting from acquisition of joint venture									0.0	(7.2)
Interest Rate Contract [Member] | Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest expense					$ 2.0				5.0	3.2
Cross-Currency Swap [Member] | Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net									(101.1)	46.2
Foreign Currency Contract - Other [Member] | Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Revenue									4.9	14.0
Foreign Currency and Coffee Contracts [Member] | Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Cost of sales including occupancy costs									$ 11.4	8.6
Starbucks Coffee Japan Ltd [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain resulting from acquisition of joint venture										$ 390.6
Preexisting ownership percentage					39.50%					39.50%