Equity (Narrative) (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($)	Dec. 31, 2019 € / shares	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Stock Repurchase Program, Authorized Amount | $					$ 1,500.0	$ 1,500.0
Authorized share capital	1,185,040,000
Ordinary shares, par value, in dollars or euros per share, as stated | $ / shares	$ 1.00	$ 1.00
Preference shares, par value, in dollars per share | $ / shares	$ 0.001
Stock Repurchased During Period, Value | $	$ 750.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount | $	$ 750.0
Ordinary shares [Member]
Number of ordinary shares	1,175,000,000
Preferred Stock [Member]
Number of preference shares	10,000,000
Preference shares outstanding	0	0
Noncontrolling interest [Member]
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Noncontrolling Interest | $	$ 0.9	$ (3.0)	$ 0.5
Euro Member Countries, Euro
Number of ordinary shares	40,000
Ordinary shares, par value, in dollars or euros per share, as stated | € / shares				€ 1.00