Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Sep. 30, 2019	Sep. 29, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 8,358.5			$ 0.0
Deferred Tax Assets, Net, Noncurrent	1,731.4			1,765.8
Deferred Revenue, Current	1,694.1			1,269.0
Income Tax Expense (Benefit)	$ 258.5	$ 205.1
Earnings per share - diluted	$ 0.74	$ 0.61
Earnings Per Share, Basic	$ 0.75	$ 0.61
Deferred Revenue, Noncurrent	$ 6,748.8			6,744.4
Deferred Tax and Other Liabilities, Noncurrent	701.2			1,370.5
Retained Earnings (Accumulated Deficit)	$ (6,414.8)			$ (5,771.2)
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset			$ 8,400.0
Retained Earnings (Accumulated Deficit)			$ 17.3