Income Taxes (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Income Tax Contingency [Line Items]
Total net deferred tax asset	$ 2.5
Capital loss carryforward	31.0
Net operating loss carryforward	18.7
Valuation allowance	52.2
Loss carryforward per year	2.8
December 31, 2025 [Member]
Income Tax Contingency [Line Items]
Loss carryforwards, amounts expiring if not utilized	17.2
December 31, 2027 [Member]
Income Tax Contingency [Line Items]
Loss carryforwards, amounts expiring if not utilized	1.5
PXRE Reinsurance Company [Member]
Income Tax Contingency [Line Items]
Reduced valuation allowance	0.7
Malta [Member]
Income Tax Contingency [Line Items]
Increased valuation allowance	0.7
Brazil [Member]
Income Tax Contingency [Line Items]
Increased valuation allowance	1.8
ARIS [Member]
Income Tax Contingency [Line Items]
Net operating loss carryforward	1.0
ARIS [Member] | December 31, 2027 [Member]
Income Tax Contingency [Line Items]
Loss carryforwards, amounts expiring if not utilized	0.2
ARIS [Member] | December 31, 2028 [Member]
Income Tax Contingency [Line Items]
Loss carryforwards, amounts expiring if not utilized	0.4
ARIS [Member] | December 31, 2029 [Member]
Income Tax Contingency [Line Items]
Loss carryforwards, amounts expiring if not utilized	$ 0.4