Investments (Details 12) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Commercial mortgage loans
Impaired mortgage loans
Recorded investment in impaired mortgage loans	$ 60.1		$ 27.3
Unpaid principal balance of impaired mortgage loans	66.3		29.7
Related allowance for impaired mortgage loans	2.7		2.4
Average investment in impaired mortgage loans	43.7	124.8
Interest income recognized on impaired mortgage loans	0.1	1.1
Brick and mortar
Impaired mortgage loans
Recorded investment in impaired mortgage loans with no related allowance	51.6		22.9
Recorded investment in impaired mortgage loans with related allowance	8.5		4.4
Unpaid principal balance of impaired mortgage loans with no related allowance	57.8		25.3
Unpaid principal balance of impaired mortgage loans with related allowance	8.5		4.4
Related allowance for impaired mortgage loans	2.7		2.4
Average investment in impaired mortgage loans with no related allowance	37.3	47.7
Average investment in impaired mortgage loans with related allowance	6.4	77.1
Interest income recognized on impaired mortgage loans with no related allowance	0.1	0.6
Interest income recognized on impaired mortgage loans with related allowance		0.5
Residential mortgage loans
Impaired mortgage loans
Recorded investment in impaired mortgage loans	35.4		39.7
Unpaid principal balance of impaired mortgage loans	35.3		36.4
Related allowance for impaired mortgage loans	10.8		10.4
Average investment in impaired mortgage loans	37.6	29.5
Interest income recognized on impaired mortgage loans	0.2	0.3
Home equity
Impaired mortgage loans
Recorded investment in impaired mortgage loans with related allowance	20.4		20.8
Unpaid principal balance of impaired mortgage loans with related allowance	20.4		20.7
Related allowance for impaired mortgage loans	9.6		9.1
Average investment in impaired mortgage loans with related allowance	20.6	15.4
Interest income recognized on impaired mortgage loans with related allowance	0.2	0.3
First liens
Impaired mortgage loans
Recorded investment in impaired mortgage loans with no related allowance	5.3		9.7
Recorded investment in impaired mortgage loans with related allowance	9.7		9.2
Unpaid principal balance of impaired mortgage loans with no related allowance	5.3		6.6
Unpaid principal balance of impaired mortgage loans with related allowance	9.6		9.1
Related allowance for impaired mortgage loans	1.2		1.3
Average investment in impaired mortgage loans with no related allowance	7.5	5.3
Average investment in impaired mortgage loans with related allowance	$ 9.5	$ 8.8

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524

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+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953550-111524

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