Investments (Changes In Commercial Mortgage Loan Loss Allowance) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Investments
Beginning balance	$ 45.6	$ 43.5	$ 48.1	$ 36.1
Provision	5.0	7.5	11.4	25.5
Charge-offs, net	(2.6)	(3.9)	(11.5)	(14.5)
Ending balance	48.0	47.1	48.0	47.1
Specific loan loss allowance	25.0	26.8	25.0	26.8	26.6
General loan loss allowance	23.0	20.3	23.0	20.3
Commercial mortgage loan loss allowance	$ 48.0	$ 47.1	$ 48.0	$ 47.1

Reflects the amount charged against earnings during the period as bad debt expense, net of recoveries of previously expensed credit losses.

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Reflects the amount of loans and leases that have been removed, or charged off, from both loan receivables and the reserve for credit losses, typically because they are considered to be not salvageable or have been purchased by unconsolidated collection entities.

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- Definition

The allowance for commercial loan and lease losses represents the reserve to cover probable credit losses related to specifically identified commercial loans and leases, as well as probable credit losses inherent in the remainder of the commercial loan portfolio as of the balance sheet date. For banks, include currently required allocated transfer risk reserves. Include carryover of or adjustments to the allowance for commercial loan losses in connection with business combinations determined to be appropriate.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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