Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Sep. 30, 2019	Dec. 30, 2018	Oct. 01, 2018	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Tax Assets, Net, Noncurrent	$ 1,533.0		$ 1,533.0				$ 123.7	$ 134.7
Deferred Revenue, Current	1,300.2		1,300.2				1,220.9	1,642.9
Income Tax Expense (Benefit)	$ 303.7	$ 174.8	$ 670.1	$ 1,086.5
Earnings per share - diluted	$ 1.12	$ 0.61	$ 2.25	$ 2.67
Earnings Per Share, Basic	$ 1.13	$ 0.62	$ 2.27	$ 2.69
Deferred Revenue, Noncurrent	$ 6,717.9		$ 6,717.9				6,839.7	6,775.7
Deferred Tax and Other Liabilities, Noncurrent	1,440.6		1,440.6				1,509.5	1,430.5
Retained Earnings (Accumulated Deficit)	$ (4,013.9)		$ (4,013.9)				$ 1,725.4	1,457.4
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						$ 227.6
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Tax Assets, Net, Noncurrent								(11.0)
Deferred Revenue, Current								(422.0)
Deferred Revenue, Noncurrent								64.0
Deferred Tax and Other Liabilities, Noncurrent								79.0
Retained Earnings (Accumulated Deficit)								$ 268.0
Forecast [Member] | Minimum [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset					$ 8,000.0
Forecast [Member] | Maximum [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset					$ 10,000.0