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Non-U.S. insurance income constituting taxable income under Sub Part F of the IRC.

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Statutory rate on the foreign source insurance income and foreign tax credit.

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Statutory tax rate

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Tax Credit Carryforward, Expiration Year

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible state and local operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from state taxes.

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Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiaries and other recognized entities not within the country of domicile of the entity.

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Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified			1 Months Ended		3 Months Ended	12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2013 United Kingdom	Apr. 30, 2012 United Kingdom	Mar. 31, 2012 United Kingdom	Dec. 31, 2013 United Kingdom	Dec. 31, 2013 United Kingdom Syndicate 1221 Maximum	Dec. 31, 2013 United Kingdom Syndicate 1221 Minimum	Dec. 31, 2013 State and Local Jurisdiction Maximum	Dec. 31, 2013 State and Local Jurisdiction Minimum
Income Taxes [Line Items]
Foreign effective income tax rate						35.00%		35.00%
Percentage of premiums							50.00%
Corporate tax rate			23.00%	24.00%	26.00%
Undistributed earnings of non-U.S. subsidiaries	$ 20.3
Taxes payable on undistributed earnings	2.1
Deferred Tax Assets: State and Local	0.6	0.5
State and local net operating loss carry-forwards	$ 0.1	$ 0.2
State and local tax carry-forwards expiration year									2031	2023