Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Ordinary Shares	Ordinary Shares Held in Treasury and Employee Benefit Trust	Capital in Excess of Par Value of Ordinary Shares	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest
Beginning balance at Dec. 31, 2017	$ 13,367.4	$ 465.1	$ (4.8)	$ 10,483.3	$ 3,406.0	$ (1,003.7)	$ 21.5
Increase (Decrease) in Stockholders' Equity
Adoption of accounting standards	(91.4)				(91.5)		0.1
Net income (loss)	201.5				200.8		0.7
Other comprehensive income (loss)	(175.4)					(176.4)	1.0
Cancellation of treasury shares	(242.0)	(7.7)		(173.7)	(60.6)
Issuance of ordinary shares	0.2	0.1		0.1
Net sales of ordinary shares for employee benefit trust	0.9		0.9
Cash dividends declared ($0.13 per share)	(120.2)				(120.2)
Share-based compensation	25.8			25.8
Other	0.9						(0.9)
Ending balance at Jun. 30, 2018	12,965.9	457.5	(3.9)	10,335.5	3,334.5	(1,180.1)	22.4
Beginning balance at Mar. 31, 2018	13,239.8	462.2	(4.0)	10,429.3	3,327.5	(991.9)	16.7
Increase (Decrease) in Stockholders' Equity
Net income (loss)	110.1				105.7		4.4
Other comprehensive income (loss)	(188.8)					(188.2)	(0.6)
Cancellation of treasury shares	(149.4)	(4.7)		(106.0)	(38.7)
Issuance of ordinary shares	0.1			0.1
Net sales of ordinary shares for employee benefit trust	0.1		0.1
Cash dividends declared ($0.13 per share)	(60.0)				(60.0)
Share-based compensation	12.9			12.9
Other	1.1			(0.8)			1.9
Ending balance at Jun. 30, 2018	12,965.9	457.5	(3.9)	10,335.5	3,334.5	(1,180.1)	22.4
Beginning balance at Dec. 31, 2018	10,388.9	450.5	(2.4)	10,197.0	1,072.2	(1,359.7)	31.3
Increase (Decrease) in Stockholders' Equity
Adoption of accounting standards	1.8				1.8
Net income (loss)	133.5				117.9		15.6
Other comprehensive income (loss)	12.7					11.4	1.3
Cancellation of treasury shares	(90.1)	(4.0)		(86.1)
Net sales of ordinary shares for employee benefit trust	2.4		2.4
Cash dividends declared ($0.13 per share)	(116.6)				(116.6)
Share-based compensation	41.5			41.5
Other	(6.3)				8.7		(2.4)
Ending balance at Jun. 30, 2019	10,380.4	446.5	0.0	10,152.4	1,084.0	(1,348.3)	45.8
Beginning balance at Mar. 31, 2019	10,373.6	448.3	0.0	10,169.5	1,047.9	(1,323.0)	30.9
Increase (Decrease) in Stockholders' Equity
Net income (loss)	113.7				97.0		16.7
Other comprehensive income (loss)	(24.7)					(25.3)	0.6
Cancellation of treasury shares	(40.0)	(1.8)		(38.2)
Cash dividends declared ($0.13 per share)	(58.1)				(58.1)
Share-based compensation	21.1			21.1
Other	(5.2)				(2.8)		(2.4)
Ending balance at Jun. 30, 2019	$ 10,380.4	$ 446.5	$ 0.0	$ 10,152.4	$ 1,084.0	$ (1,348.3)	$ 45.8