Condensed Consolidated Statement of Changes in Shareholders' Equity Statement - 3 months ended Mar. 31, 2017 - USD ($) $ in Millions	Total	Ordinary Shares	Treasury Shares	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance, ordinary shares (in shares) at Dec. 30, 2016	118,182,944	118,200,000
Beginning balance, treasury shares (in shares) at Dec. 30, 2016	13,515,399		13,500,000
Beginning balance at Dec. 30, 2016	$ 4,984.3	$ 23.6	$ (919.8)	$ 5,424.0	$ 529.0	$ (72.5)
Impact of accounting standard adoptions	(72.1)				(72.1)
Net income	399.2
Currency translation adjustments	2.4					2.4
Change in derivatives, net of tax	0.2					0.2
Unrecognized gain on benefit plans	46.6					46.6
Unrecognized gain on investments	13.4					13.4
Share options exercised (in shares)		100,000
Share options exercised (in usd)	2.2	$ 0.0		2.2
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		300,000
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	(4.0)	$ 0.1	(4.0)	(0.1)
Share-based compensation	16.4			16.4
Stock Issued During Period, Value, Treasury Stock Reissued	1.2		$ 1.7		(0.5)
Repurchase of shares (in shares)			5,700,000
Repurchase of shares (in usd)	$ 275.6		$ (275.6)
Ending balance, ordinary shares (in shares) at Mar. 31, 2017	118,559,940	118,600,000
Ending balance, treasury shares (in shares) at Mar. 31, 2017	19,156,660		19,200,000
Ending balance at Mar. 31, 2017	$ 5,114.2	$ 23.7	$ (1,197.7)	$ 5,442.5	$ 855.6	$ (9.9)