Derivative Financial Instruments Derivative Financial Instruments (Narrative) (Details) $ in Millions, ¥ in Billions	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 28, 2015 JPY (¥)	Jun. 28, 2015 USD ($)	Jun. 29, 2014 USD ($)	Jun. 28, 2015 USD ($)		Jun. 29, 2014 USD ($)	Jun. 28, 2015 USD ($)	Dec. 28, 2014 USD ($)	Sep. 28, 2014 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain resulting from acquisition of joint venture		$ 0.0	$ 0.0	$ 390.6		$ 0.0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Investment Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain resulting from acquisition of joint venture				7.2	[1]	$ 0.0
Starbucks Coffee Japan Ltd Member
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain resulting from acquisition of joint venture				390.6
Preexisting ownership percentage in Starbucks Japan									39.50%
Starbucks Coffee Japan Ltd Member | Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Investment Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Gain resulting from acquisition of joint venture				$ 7.2
Two Point Seven Percentage Senior Notes [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount								$ 250.0
Debt Instrument, Face Value							$ 500.0		$ 0.0
Stated Interest Rate	2.70%						2.70%
Debt Instrument, Maturity	Jun. 15, 2022
Four Point Three Percentage Senior Notes [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Debt Instrument, Face Value							$ 350.0		0.0
Stated Interest Rate	4.30%						4.30%
Debt Instrument, Maturity	Jun. 15, 2045
Interest Rate Swap [Member] | Four Point Three Percentage Senior Notes [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount							$ 250.0
Cross-Currency Swap [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	¥ 86.5						$ 698.0		$ 0.0

[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.