Fair Value Of Assets And Liabilities (Reconciliation Of Balance, Fair Value Measurement, Level 3) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Underlying investment in CLO's	$ 50.4
Sales recorded relating the CLO investment	187.6
CLO investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	0.5		17.9
Adoption of guidance now encompassed in ASC Topic 810	0	[1]	(17.4)	[1]
Beginning Balance, as adjusted (Asset)	0.5		0.5
Net unrealized gains and losses included in accumulated other comprehensive income/(loss) (Asset)	0	[2]	0.1	[2]
Gain and losses included in the Condensed Consolidated Statement of Income, level 3 assets	0		0
Purchases, sales, issuances, and settlements, net (Asset)	(0.5)	[3]	(0.1)	[3]
Ending balance	0		0.5
Sales recorded relating the CLO investment	0.4
CLO return of capital	(0.1)
Note Payable [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance (Liability)	(18.9)
Net unrealized gains and losses included in accumulated other comprehensive income/(loss) (Liability)	0	[2]
Foreign exchange movements included in earnings (Liability)	(0.8)
Purchases, sales, issuances, and settlements, net (Liability)	2.9	[3]
Ending Balance (Liability)	$ (16.8)

[1] The company adopted guidance now encompassed in ASC Topic 810 on January 1, 2010, resulting in the consolidation of CLOs for which the company has an underlying investment of $50.4 million at December 31, 2011 (before consolidation). The adjustment of $17.4 million in the table above reflects the elimination of the company's equity interest upon adoption. In accordance with the standard, prior periods have not been restated to reflect the consolidation of these CLOs.**There were no net unrealized gains and losses included in accumulated other comprehensive income/(loss) for the year ended December 31, 2011 as assets was sold in the year ended December 31, 2011 (year ended December 31, 2010: $0.1 million attributed to the change in unrealized gains and losses related to assets still held at December 31, 2010).

[2] There were no net unrealized gains and losses included in accumulated other comprehensive income/(loss) for the year ended December 31, 2011 as assets was sold in the year ended December 31, 2011 (year ended December 31, 2010: $0.1 million attributed to the change in unrealized gains and losses related to assets still held at December 31, 2010).

[3] Prior to the adoption of guidance included in ASU 2010-06, discussed in Note 1, “Accounting Policies,” purchases, sales, issuances, and settlements were presented net. For the year ended December 31, 2011 there was $0.1 million of return of capital and a sale of $0.4 million related to the CLO investment (year ended December 31, 2010: $0.1 million return of capital activity). For the year ended December 31, 2011, there was $2.9 million in settlement activity related to the note payable.