Taxation (Pretax Income from Continuing Operations and Provision for Income Taxes) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of pre tax income from continuing operations
Income from continuing operations before income taxes and equity in earnings of equity method investees (in USD)	$ 3,336.2	$ 1,693.6	$ 1,007.8
Current income taxes:
Total current taxes	26.2	355.6	270.3
Deferred taxes:
Total deferred taxes	29.9	(77.7)	(67.2)
Total income taxes	56.1	277.9	203.1
US federal tax
Current income taxes:
Current foreign tax expense (benefit)	291.8	274.3	230.0
Deferred taxes:
Deferred foreign tax expense (benefit)	39.7	23.8	(63.8)
UK corporation tax
Deferred taxes:
Deferred foreign tax expense (benefit)	(3.0)	11.5	13.1
Other
Current income taxes:
Other, current	(290.9)	63.4	29.0
Deferred taxes:
Other, deferred	(3.9)	(104.7)	(10.0)
US state and local taxes
Current income taxes:
Current foreign tax expense (benefit)	25.3	17.9	11.3
Deferred taxes:
Deferred foreign tax expense (benefit)	(2.9)	(8.3)	(6.5)
Ireland
Components of pre tax income from continuing operations
Republic of Ireland	1,472.0	(47.8)	(74.7)
United Kingdom
Components of pre tax income from continuing operations
Pre-tax income from continuing operations, foreign	63.1	10.9	30.7
United States
Components of pre tax income from continuing operations
Pre-tax income from continuing operations, foreign	1,025.9	1,153.3	683.8
Other jurisdictions
Components of pre tax income from continuing operations
Pre-tax income from continuing operations, foreign	$ 775.2	$ 577.2	$ 368.0