Income Taxes (Carryforward) (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
[DomesticCountryMember] | [CorporateTaxMember] | [NetOperatingLossCarryforwardMember]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 177,206	$ 106,535
Operating Loss Carryforwards Expiration Dates	2023 - 2032	2023 - 2031
[DomesticCountryMember] | [CapitalGainsTaxMember] | [CapitalLossCarryforwardMember]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards Expiration Dates	2015	2015
Deferred Tax Assets Capital Loss Carryforwards	1,848	1,848
[GB]
Operating Loss Carryforwards [Line Items]
Income Tax Examination Year Under Examination	2011
[GB] | [CorporateTaxMember] | [NetOperatingLossCarryforwardMember]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	500,789	228,701
Operating Loss Carryforwards Expiration Dates	Indefinite	Indefinite
[GB] | [SupplementalCorporateTaxMember] | [NetOperatingLossCarryforwardMember]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 378,602	$ 159,316
Operating Loss Carryforwards Expiration Dates	Indefinite	Indefinite
[NonUnitedKingdomTaxJuristictionMember] | [MinimumMember]
Operating Loss Carryforwards [Line Items]
Income Tax Examination Year Under Examination	2009
[NonUnitedKingdomTaxJuristictionMember] | [MaximumMember]
Operating Loss Carryforwards [Line Items]
Income Tax Examination Year Under Examination	2011