Increase in additional paid in capital due to gain on sale of business unit during the reporting period.

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Increase in additional paid in capital due to gain on sale of business unit during the reporting period, net of transaction costs expensed through the statement of operations.

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No definition available.

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- Definition

The percentage of the AutoOne business written by the entity which is ceded on a quota share basis.

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No definition available.

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- Definition

The percentage of the insurance companies which is ceded on a quota share basis by the entity on execution of agreement.

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No definition available.

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- Definition

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

+ References

No definition available.

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Represents the amount of underwriting expenses, net of tax attributable to the disposal group, including a component of the entity (discontinued operation), during the reporting period.

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No definition available.

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- Definition

Represents the after tax gain (loss) from adverse prior year loss reserve.

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No definition available.

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- Definition

Amount of operating expenses to be deducted from prepayment of principal upon receipt of dividend or distribution related to promissory note.

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No definition available.

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- Definition

Represents the after tax provision for benefits, claims and claims settlement expenses incurred during the period net of the effects of contracts assumed and ceded.

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No definition available.

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- Definition

Amount of principal required to be pre-paid as a percentage of any dividend or distribution for Interboro received from its subsidiaries, net of taxes and less operating expenses.

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No definition available.

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- Definition

A written promise to pay a note to OneBeacon.

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No definition available.

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- Definition

The cash inflow from a loan, supported by a promissory note.

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No definition available.

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- Definition

Represents the term of the service agreement.

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No definition available.

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- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

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No definition available.

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- Definition

Gain (loss) after tax expense or benefit, not previously recognized and resulting from the sale of a business component, which is recognized at the date of sale. A gain (loss) reflects the amount by which the consideration received exceeds (is exceeded by) the net carrying amount (reflecting previous provisions for loss on disposal, if any) of the disposal group.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 45

-Paragraph 3

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 43

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-SubTopic 20

-Section 50

-Paragraph 1

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- Definition

The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or the sale of investment in consolidated subsidiaries (generally greater than 50 percent).

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 45

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-Name Accounting Standards Codification

-Glossary Investing Activities

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- Definition

Alternate concept name for the aggregate amount of policy reserves (provided for future obligations including unpaid claims and claims adjustment expenses) and policy benefits (liability for future policy benefits) as of the balance sheet date; grouped amount of all the liabilities associated with the company's insurance policies.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

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-Subparagraph (SX 210.7-03.13(a)(1))

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-Name Statement of Financial Accounting Standard (FAS)

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-Publisher AICPA

-Name Statement of Position (SOP)

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-Paragraph 11

-Subparagraph a

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 13

-Subparagraph a

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Acqusitions and Dispositions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended									9 Months Ended	1 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Feb. 22, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010	Sep. 30, 2012 Specialty Insurance Operations	Dec. 31, 2011 Specialty Insurance Operations	Sep. 30, 2012 TSA	Jan. 31, 2012 OneBeacon Holdings (Luxembourg) S.a r.l.	Jan. 24, 2012 OneBeacon Holdings (Luxembourg) S.a r.l.	Oct. 01, 2012 ASIC	Sep. 30, 2012 AutoOne business	Sep. 30, 2012 AutoOne business Interboro LLC	Sep. 30, 2012 Runoff	Oct. 01, 2012 Runoff ASIC	Sep. 30, 2012 Runoff OneBeacon
Dispositions
Ceded share of insurance companies on execution of agreement (as a percent)														100.00%				100.00%
Initial term of the service agreement											1 year
Loss and loss adjustment expense reserves		$ 911.6	$ 3,175.3		$ 3,358.6	$ 3,159.1	$ 3,131.5	$ 3,295.5	$ 911.4	$ 868.6							$ 36.7
Loss on sale of discontinued operation, net of tax																	91.5		107.0
Estimated loss on sale of discontinued operation, net of tax																			91.5
Loss and LAE, after tax																	9.0		9.0
After tax losses primarily related to adverse prior year loss reserve development related to a legacy assumed reinsurance treaty																			6.5
Ceded share of AutoOne business (as a percent)				100.00%
After tax net charge related to underwriting activity															0.3				6.5
Promissory note issued																3.0
Repayment of promissory note																1.0
Prepayment of principal on promissory note (as a percent)																100.00%
Prepayment of principal on promissory note (as a percent)																0.2
Interest rate base																LIBOR
Interest rate margin (as a percent)																5.50%
Proceeds from sale of subsidiary												24.7
Gain on sale of OneBeacon Holdings (Luxembourg) S.a r.l.	14.0	(14.0)										14.0
Gain on sale of subsidiary, net of transaction costs		$ 13.6											$ 13.6