Condensed Consolidated Statements of Shareholders' Equity Statement - USD ($) shares in Millions, $ in Millions	Total	Ordinary Shares Issued	Accumulated Other Comprehensive Income	Retained Earnings (Accumulated Deficit)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards | Adoption of new accounting standards	$ 5.3		$ (1.0)	$ 6.3
Beginning balance (shares) at Dec. 31, 2017		140.8
Balance, beginning at Dec. 31, 2017	6,170.5	$ 7,892.9	253.1	(1,975.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	80.8
Other comprehensive income (loss)	72.2		72.2
Stock options exercised	0.2	$ 0.2
Restricted stock plan (shares)		0.2
Compensation for stock options	2.7	$ 2.7
Compensation for restricted stock	10.0	10.0
Cash dividends, $0.19 per share	(26.7)	(26.7)
Shares withheld for payment of employees' withholding tax liability	(1.5)	$ (1.5)
Repurchases of ordinary shares (shares)		(1.3)
Repurchases of ordinary shares	(108.1)	$ (108.1)
Ending balance (shares) at Mar. 31, 2018		139.7
Balance, ending at Mar. 31, 2018	6,205.4	$ 7,769.5	324.3	(1,888.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards | Adoption of new accounting standards	(3.4)			(3.4)
Beginning balance (shares) at Dec. 31, 2018		135.9
Balance, beginning at Dec. 31, 2018	5,668.0	$ 7,421.7	84.6	(1,838.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	63.9
Other comprehensive income (loss)	(15.6)		(15.6)
Restricted stock plan (shares)		0.2
Compensation for stock options	1.8	$ 1.8
Compensation for restricted stock	14.2	14.2
Cash dividends, $0.19 per share	(25.9)	$ (25.9)
Shares withheld for payment of employees' withholding tax liability (shares)		(0.1)
Shares withheld for payment of employees' withholding tax liability	$ (2.4)	$ (2.4)
Repurchases of ordinary shares (shares)	0.0
Ending balance (shares) at Mar. 30, 2019		136.0
Balance, ending at Mar. 30, 2019	$ 5,700.6	$ 7,409.4	$ 69.0	$ (1,777.8)