Equity (Impact of Reclassifications from Accumulated Other Comprehensive Income on Earnings) (Details) - USD ($) $ in Millions		3 Months Ended
		Dec. 27, 2015	Dec. 28, 2014	Sep. 28, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest expense		$ (16.5)	$ (16.3)
Amounts Reclassified from AOCI, Interest income and other, net		8.1	9.7
Amounts Reclassified from AOCI, Revenues		5,373.5	4,803.2
Amounts Reclassified from AOCI, Cost of sales including occupancy costs		(2,186.2)	(1,991.2)
Gain resulting from acquisition of joint venture		0.0	390.6
Amounts Reclassified from AOCI, Tax (expense)/benefit		(361.9)	(315.0)
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		8.1	59.6
Amounts Reclassified from AOCI, Tax (expense)/benefit		(2.8)	(17.1)
Amounts Reclassified from AOCI		5.3	42.5
Net Investment Hedging [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI		0.0	(4.6)
Net Investment Hedging [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	[1]	0.0	7.2
Translation Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI		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	[2]	0.0	(7.1)
Gain resulting from acquisition of joint venture	[2]	0.0	(7.2)
Interest Rate Contract [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying 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		1.5	1.3
Cross-Currency Swap [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying 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		(1.8)	63.1
Foreign Currency Contract - Other [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying 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, Revenues		3.1	2.5
Foreign Currency and Coffee Contracts [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying 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		$ 5.3	(0.2)
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 in Starbucks Japan				39.50%

[1] Release of pretax cumulative net gains in AOCI related to our net investment derivative instruments used to hedge our preexisting 39.5% equity method investment in Starbucks Japan.

[2] Release of cumulative translation adjustments to earnings upon sale or liquidation of foreign business.