Financing and Capital Capital (Details) $ / shares in Units, $ in Millions				9 Months Ended
	Sep. 28, 2018 $ / shares shares	Sep. 26, 2018 day shares	Jun. 29, 2018 USD ($) $ / shares shares	Sep. 28, 2018 USD ($) $ / shares shares	Sep. 29, 2017 USD ($)	Dec. 31, 2017 $ / shares shares
Schedule of Capitalization [Line Items]
Preferred stock issued (in shares) | shares	1,400,000			1,400,000		0
Preferred stock par value (in dollars per share) | $ / shares	$ 0.01			$ 0.01		$ 0.01
Proceeds from issuance of mandatory convertible preferred stock net of $43 million of issuance costs | $				$ 1,337.4	$ 0.0
Payments of stock issuance costs | $				$ 43.0
Dividend per share on MCPS (in dollars per share) | $ / shares	12.78
Preferred Stock
Schedule of Capitalization [Line Items]
Preferred stock issued (in shares) | shares			1,380,000
Preferred stock, dividend rate, percentage			5.00%	5.00%
Preferred stock par value (in dollars per share) | $ / shares			$ 0.01
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares	1,000		$ 1,000	$ 1,000
Preferred stock, over-allotment shares issued (in shares) | shares			180,000
Proceeds from issuance of mandatory convertible preferred stock net of $43 million of issuance costs | $			$ 1,340.0
Payments of stock issuance costs | $			$ 43.0
Convertible preferred stock, shares issued upon conversion | shares		10.9041
Debt instrument, convertible, threshold consecutive trading days | day		20
Preferred stock, dividend rate, per-dollar-amount (in dollars per share) | $ / shares				$ 50.00
Dividend per share on MCPS (in dollars per share) | $ / shares	$ 12.78
Minimum | Preferred Stock
Schedule of Capitalization [Line Items]
Convertible preferred stock, shares issued upon conversion | shares		10.9041
Maximum | Preferred Stock
Schedule of Capitalization [Line Items]
Convertible preferred stock, shares issued upon conversion | shares		13.3575