Acquisitions and Divestitures (Allocation of Total Consideration to Fair Value of Assets Acquired and Liabilities Assumed) (Details)		3 Months Ended		12 Months Ended
	Dec. 31, 2017 USD ($)	Jun. 30, 2019 USD ($)	Apr. 01, 2018 USD ($)	Sep. 27, 2020 USD ($)	Sep. 29, 2019 USD ($)	Sep. 30, 2018 USD ($)
Goodwill				$ 3,597,200,000	$ 3,490,800,000	$ 3,541,600,000
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination	$ 2,972,100,000
Gain resulting from acquisition of joint venture				0	$ 0	1,376,400,000
President Starbucks Coffee Taiwan Ltd. [Member]
Proceeds from Sales of Business, Affiliate and Productive Assets			$ 181,200,000
Deconsolidation, Gain (Loss), Amount			156,600,000
Starbucks Coffee Thailand [Member]
Deconsolidation, Gain (Loss), Amount		$ 601,900,000
East China JV [Member]
Business Combination, Acquisition Related Costs						3,600,000
Goodwill				2,100,000,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual						903,000,000.0
Finite-Lived Intangible Assets, Amortization Expense, Next Rolling Twelve Months				157,800,000
Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Four				154,400,000
Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Three				157,800,000
Goodwill, Foreign Currency Translation Gain (Loss)				$ 102,800,000
Business Combination, Consideration Transferred			1,400,000,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual						73,100,000
Business Acquisition, Pro Forma Revenue						24,990,400,000
Business Acquisition, Pro Forma Net Income (Loss)						3,196,800,000
Business Acquisition, Effective Date of Acquisition	Dec. 31, 2017
Payments to Acquire Interest in Joint Venture	$ 1,440,800,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value	1,440,800,000					1,400,000,000
Business Combination, Separately Recognized Transactions, Liabilities Recognized	90,500,000
Cash and cash equivalents	129,500,000
Accounts receivable, net	14,300,000
Inventories	16,100,000
Prepaid expenses and other current assets	20,600,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	2,164,100,000
Property, plant and equipment	254,100,000
Other long-term assets	44,600,000
Total assets acquired	3,461,300,000
Accounts payable	(34,700,000)
Stored value card liability	(21,700,000)
Other long-term liabilities	(245,100,000)
Total liabilities assumed	489,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	818,000,000.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	187,700,000
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination	$ 2,972,100,000
Number of Stores	1,400
Gain resulting from acquisition of joint venture						$ 1,400,000,000
East China JV [Member] | Acquired and reacquired rights [Member]
Finite-lived Intangible Assets Acquired	$ 798,000,000.0
Tazo business [Member]
Proceeds from Divestiture of Businesses			383,800,000
Deconsolidation, Gain (Loss), Amount			$ 347,900,000