Contractual interest rate for funds borrowed, under the debt agreement.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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Amount of gain (loss), after tax expense or benefit and not previously recognized, resulting from the sale of a business component.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e957-107759

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-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

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Financial instruments issued by insurance entities (surplus notes) that are includable in surplus for statutory accounting purposes as prescribed or permitted by state laws and regulations that are liabilities of the issuer.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 470

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6486086&loc=d3e24387-158525

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Current market rates on public debt and contract-based repayments.

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Liquidity spread relating to lack of trading market and ongoing regulatory approval risk.

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Discontinued Operations Discontinued Operations (Surplus Note Table) (Details) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 23, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions
(Loss) gain on sale of discontinued operations, net of tax	$ (1.6)	$ 46.6	$ (91.0)
OneBeacon Runoff
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Surplus notes				101.0
OneBeacon Runoff \| Other long-term investments \| Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Surplus notes				64.9
OneBeacon Runoff \| Surplus Note
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Percentage of Total Adjusted Capital	200.00%
OneBeacon Runoff \| Surplus Note \| Other long-term investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Interest rate (as a percent)				6.00%
Discontinued Operations
Fair Value, Balance Sheet Grouping, Financial Statement Captions
(Loss) gain on sale of discontinued operations, net of tax	(1.6)	46.6	(91.0)
Discontinued Operations \| OneBeacon Runoff
Fair Value, Balance Sheet Grouping, Financial Statement Captions
RBC Score	250.00%
Current Market Rate	(6.6)
Regulatory Approval Payment	(12.6)
Liquidity Adjustments	(16.7)
(Loss) gain on sale of discontinued operations, net of tax	(35.9)		91.5
Surplus notes	101.0
Discontinued Operations \| OneBeacon Runoff \| Seller Priority Surplus Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Current Market Rate	1.6
Regulatory Approval Payment	(4.6)
Liquidity Adjustments	(11.0)
(Loss) gain on sale of discontinued operations, net of tax	(14.0)
Surplus notes	57.9
Discontinued Operations \| OneBeacon Runoff \| Pari Passu Surplus Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Current Market Rate	(8.2)
Regulatory Approval Payment	(8.0)
Liquidity Adjustments	(5.7)
(Loss) gain on sale of discontinued operations, net of tax	(21.9)
Surplus notes	43.1
Discontinued Operations \| OneBeacon Runoff \| Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Surplus notes	65.1
Discontinued Operations \| OneBeacon Runoff \| Fair Value [Member] \| Seller Priority Surplus Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Surplus notes	43.9
Discontinued Operations \| OneBeacon Runoff \| Fair Value [Member] \| Pari Passu Surplus Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Surplus notes	21.2
Discontinued Operations \| OneBeacon Runoff \| Surplus Note
Fair Value, Balance Sheet Grouping, Financial Statement Captions
(Loss) gain on sale of discontinued operations, net of tax	$ (23.5)