Taxation (Operating Loss and Tax Credit Carryforwards, and Their Expiration Dates) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Operating Loss and Tax Credit Carryforwards
Gross value of NOLs and capital losses	$ 1,610.1	$ 1,178.3
Expirations of Tax Benefit Carryforwards
Within 1 year	0.1
Winthin 1 to 2 years	0
Winthin 2 to 3 years	0.8
Winthin 3 to 4 years	1.1
Winthin 4 to 5 years	1.8
Winthin 5 to 6 years	3.3
After 6 years	115.4
Indefinitely	262.2
Unremitted earnings of the Company's foreign subsidiaries	6,200	5,800
R&D
Operating Loss and Tax Credit Carryforwards
Tax credit carryforwards	62.1	106.2
US Federal
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards After Tax Effect	45.3	14.7
US State
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards After Tax Effect	19.8	16.6
United Kingdom
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards After Tax Effect	24.8	30.4
Ireland
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards After Tax Effect	58.0	66.0
Foreign Tax Jurisdictions
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards After Tax Effect	$ 174.7	$ 80.4