Fair Value Of Assets And Liabilities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 13.2		$ 13.2		$ 0	$ 0
Number of futures contracts (as shown)	4		4			10
Purchased Put Option [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative maximum exposure	0	0	1.8	2.5
Loss on derivative	1.1	1.2	1.8	2.4
Future [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value of futures contracts	0.5		0.5			1.4
Note Payable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	1.2	11.3	1.2	11.3	1.2	3.4	12.6	16.8
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0	0	0.1	3.5
Net unrealized gains and losses included in accumulated other comprehensive income/(loss)	0	0	0	0
CLOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	2.2	2.5	2.2	2.5	2.4	2.4	2.5	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0	0	0	0
Net unrealized gains and losses included in accumulated other comprehensive income/(loss)	(0.1)	0	0	0.2
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	6.3	6.3	6.3	6.3	6.3	6.3	6.3	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0	0	0	0
Net unrealized gains and losses included in accumulated other comprehensive income/(loss)	$ 0	$ 0	$ 0	$ 0