Summary of Significant Accounting Policies Significant Accounting Policies Additional Disclosures (Details) - USD ($)	3 Months Ended									12 Months Ended
	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Jan. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Oct. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Revenue, Current		$ 1,642,900,000				$ 1,288,500,000				$ 1,642,900,000	$ 1,288,500,000
Goodwill, Impairment Loss										37,600,000	87,200,000	$ 0
Income Tax Expense (Benefit)										$ 1,262,000,000	$ 1,432,600,000	$ 1,379,700,000
Earnings Per Share, Basic										$ 3.27	$ 1.99	$ 1.91
Earnings Per Share, Diluted		$ 0.56	$ 0.61	$ 0.47	$ 1.57	$ 0.54	$ 0.47	$ 0.45	$ 0.51	$ 3.24	$ 1.97	$ 1.90
Deferred Revenue, Noncurrent		$ 6,775,700,000				$ 4,400,000				$ 6,775,700,000	$ 4,400,000
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income Tax Expense (Benefit)										60,200,000
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification										$ 60,200,000
Earnings Per Share, Basic										$ 40,000.00
Earnings Per Share, Diluted										$ 0.04
Excess Tax Benefit from Share-based Compensation, Financing Activities											$ 77,500,000	$ 122,800,000
Scenario, Forecast [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 300,000,000