Acquisitions and Divestitures (Narrative) (Details) ¥ in Millions, $ in Millions								3 Months Ended									8 Months Ended	12 Months Ended
	Jun. 12, 2015 JPY (¥)	Jun. 12, 2015 USD ($)	Mar. 26, 2015	Dec. 29, 2014 JPY (¥)	Dec. 29, 2014 USD ($)	Oct. 31, 2014 JPY (¥)	Oct. 31, 2014 USD ($)	Sep. 27, 2015 JPY (¥)	Sep. 27, 2015 USD ($)	Jun. 28, 2015 JPY (¥)	Jun. 28, 2015 USD ($)	Sep. 28, 2014 USD ($)	Sep. 29, 2013 USD ($)	Jun. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2013 USD ($)	Jun. 28, 2015 USD ($)	Oct. 02, 2016 JPY (¥)	Oct. 02, 2016 USD ($)	Sep. 27, 2015 USD ($)	Sep. 28, 2014 USD ($)	Sep. 29, 2013 USD ($)	Dec. 28, 2014	Oct. 26, 2014	Dec. 31, 2012 USD ($)
Business Acquisition [Line Items]
Finite-lived intangible assets, amortization expense																				$ 50.0	$ 8.7	$ 7.7
Unfavorable/favorable leases, rent expense/(reduction)																				1,137.8	974.2	894.7
Gain resulting from acquisition of joint venture																				$ 390.6	$ 0.0	$ 0.0
Puerto Rico Retail Operations [Member]
Business Acquisition [Line Items]
Total proceeds from sale of retail store assets and operations									$ 8.9
Gain/(loss) resulting from divestiture									3.7
Starbucks Coffee Japan Ltd [Member]
Business Acquisition [Line Items]
Preexisting ownership percentage												39.50%									39.50%
Remaining Ownership Interest in Equity Method Investee to be Acquired												60.50%									60.50%
Reason for acquisition																				Acquiring Starbucks Japan further leverages our existing infrastructure to continue disciplined retail store growth and expand our presence into other channels in the Japan market, such as consumer packaged goods ("CPG"), licensing and foodservice
Additional ownership interest acquired				14.70%	14.70%		39.50%
Cash paid to acquire additional ownership interest	¥ 13,500	$ 109.0		¥ 31,000	$ 258.0	¥ 55,000	$ 508.7	¥ 3,200	$ 26.0	¥ 9,600	$ 78.0
Total ownership interest in Starbucks Japan acquired through first tender offer step							79.00%
Remaining interest of minority shareholders' to be acquired			6.30%				21.00%																21.00%
Ownership interest after conclusion of Cash-out procedure			100.00%
Reference conversion rate				120.39	120.39				120.72	123.87	123.87						123.87			120.72				108.13
Acquisition-related costs incurred																				$ 11.9
Acquisition date						Oct. 31, 2014	Oct. 31, 2014
Finite-lived intangible assets, effect of foreign currency translation																	$ (33.7)
Finite-lived intangible assets, amortization expense																				41.0
Acquired finite-lived intangible assets, amortization expense, next twelve months									$ 44.0											44.0
Acquired finite-lived intangible assets, amortization expense, year two									44.0											44.0
Acquired finite-lived intangible assets, amortization expense, year three									44.0											44.0
Acquired finite-lived intangible assets, amortization expense, year four									44.0											44.0
Acquired finite-lived intangible assets, amortization expense, year five									44.0											44.0
Acquired finite-lived intangible assets, amortization expense, after year five									$ 29.0											29.0
Goodwill							$ 815.6													730.5
Goodwill description						the intangible assets that do not qualify for separate recognition and primarily includes the acquired customer base, the acquired workforce including store partners in the region that have strong relationships with these customers, the existing geographic retail and online presence, and the expected geographic presence in new channels	the intangible assets that do not qualify for separate recognition and primarily includes the acquired customer base, the acquired workforce including store partners in the region that have strong relationships with these customers, the existing geographic retail and online presence, and the expected geographic presence in new channels
Goodwill, effect of foreign currency translation																				(85.1)
Favorable lease assets acquired							$ 7.5
Unfavorable lease liabilities assumed							$ 15.5
Favorable lease assets and unfavorable lease liabilities, weighted average remaining term (years)						9 years 4 months 24 days	9 years 4 months 24 days
Unfavorable/favorable leases, rent expense/(reduction)																				(0.8)
Gain resulting from acquisition of joint venture																				390.6
Fair value of preexisting equity interest							$ 577.0
Revenue included in consolidated statements of earnings																				1,100.0
Net earnings included in consolidated statements of earnings																				108.5
Pro forma revenue																				19,254.5	$ 17,646.4
Pro forma net earnings attributable to Starbucks																				2,380.9	$ 2,449.9
Transaction and integration costs																				$ 13.6
Starbucks Coffee Japan Ltd [Member] | Scenario, Forecast [Member]
Business Acquisition [Line Items]
Cash paid to acquire additional ownership interest																		¥ 674	$ 6.0
Starbucks Coffee Japan Ltd [Member] | Acquired and reacquired rights [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							$ 305.0
Finite-lived intangible assets, life (years)						6 years 4 months 24 days	6 years 4 months 24 days
Starbucks Coffee Japan Ltd [Member] | Licensing agreements [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							$ 15.0
Finite-lived intangible assets, life (years)						10 years 10 months 24 days	10 years 10 months 24 days
Starbucks Coffee Japan Ltd [Member] | Customer loyalty program [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired							$ 3.0
Finite-lived intangible assets, life (years)						4 years	4 years
Australia Retail Operations [Member]
Business Acquisition [Line Items]
Total proceeds from sale of retail store assets and operations												$ 15.9
Gain/(loss) resulting from divestiture												$ 2.4
Starbucks Chile [Member]
Business Acquisition [Line Items]
Gain/(loss) resulting from divestiture													$ 45.9
Ownership interest sold to joint venture partner													82.00%									82.00%
Purchase price of joint venture sold													$ 68.6
Costa Rica Coffee Farm [Member]
Business Acquisition [Line Items]
Additional ownership interest acquired														100.00%
Cash paid to acquire additional ownership interest														$ 8.1
Teavana [Member]
Business Acquisition [Line Items]
Reason for acquisition															to elevate our tea offerings as well as expand our domestic and global tea footprint
Additional ownership interest acquired																									100.00%
Cash paid to acquire additional ownership interest															$ 615.8
Acquisition date															Dec. 31, 2012
Goodwill																$ 467.5
Goodwill description																the intangible assets that do not qualify for separate recognition, primarily including Teavana's established global store presence in high traffic mall locations and other high-sales-volume retail venues, Teavana's global customer base, and Teavana's "Heaven of tea" retail experience in which store employees engage and educate customers about the ritual and enjoyment of tea
Contingent consideration receivable																									$ 12.2
Long-term debt repaid at closing																									$ 35.2
Teavana [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired																$ 105.5
Teavana [Member] | Acquired trade secrets and processes [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired																$ 13.0
Finite-lived intangible assets, life (years)																10 years
Teavana [Member] | Noncompete Agreements [Member]
Business Acquisition [Line Items]
Finite-lived intangible assets acquired																$ 2.3
Finite-lived intangible assets, life (years)																3 years