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Long-Term Debt Narrative (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
Long-Term Debt Narrative (Details) - USD ($) $ in Millions	Jun. 12, 2019	Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Debt issuance costs		$ 29.3		$ 29.3		$ 33.5
Long-term debt		3,805.8		3,805.8
Debt, principal balance outstanding		3,805.8		3,805.8		2,939.0
Maximum Borrowing Capacity	$ 1,900.0
Legal Fees	6.5
Loss on debt refinancing and prepayment	$ 0.4	(0.4)	$ (4.0)	(0.4)	$ (4.0)
1.00% Notes \| Convertible Debt
Debt Instrument [Line Items]
Debt issuance costs		$ 4.4		$ 4.4		5.8
Debt instrument, interest rate (as a percent)		1.00%		1.00%
Debt, principal balance outstanding		$ 690.0		$ 690.0		$ 690.0