Taxation (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Tax Assets, Net	$ 15.1	$ 18.3
Deferred tax liabilities, net	$ 288.9	$ 304.8
Statutory tax rate	35.00%	35.00%	35.00%
Deferred Tax Assets, Operating Loss Carryforwards	$ (229.0)	$ (285.1)
Unremitted Foreign Earnings	839.8	969.9
Deferred Tax Liabilities, Undistributed Foreign Earnings	1.5	1.6
Unrecognized Tax Benefits	9.6	6.0	$ 16.8	$ 22.6
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	8.8
Income Tax Expense (Benefit)	398.0	390.6	336.9
Expiring In Next Five Fiscal Years [Member]
Deferred Tax Assets, Operating Loss Carryforwards	(39.2)
Expiring In After Five Fiscal Years [Member]
Deferred Tax Assets, Operating Loss Carryforwards	(12.6)
Indefinite Life [Member]
Deferred Tax Assets, Operating Loss Carryforwards	(177.2)
Change during the period [Member]
Deferred Tax Assets, Operating Loss Carryforwards	(56.1)
Impact of foreign exchange translation [Member]
Deferred Tax Assets, Operating Loss Carryforwards	(22.0)
Forfeiture of losses resulting from liquidations or mergers [Member]
Deferred Tax Assets, Operating Loss Carryforwards	$ (4.0)
United Kingdom
Statutory tax rate	20.00%
Canada
Dividends Withholding Tax Rate	5.00%
United States
Statutory tax rate	35.00%
Related to accrued interest and penalties [Member]
Income Tax Examination, Penalties and Interest Accrued	$ 1.2	1.0	5.1
Income Tax Expense (Benefit)	0.9	$ 3.8	$ 0.4
Minimum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	0.0
Maximum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	$ 5.0