Income Taxes - Components of Net Deferred Tax Asset (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred federal income tax asset:
Losses and loss adjustments expenses		$ 143
Net operating loss carryforward	2,098,597	2,087,490
Accruals and reserves	4,531	16,387
As filed adjustments	214	130
Capital loss carryforward	52,603	52,756
Total deferred federal income tax asset	2,155,945us-gaap_DeferredTaxAssetsGross	2,156,906us-gaap_DeferredTaxAssetsGross
Deferred federal income tax liabilities:
Net unrealized gains on investments	154	425
Losses and loss adjustments expenses	102
Total deferred federal income tax liabilities	256us-gaap_DeferredIncomeTaxLiabilities	425us-gaap_DeferredIncomeTaxLiabilities
Less: Valuation allowance	$ 2,155,689	$ 2,156,481

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Amount of deferred tax liability attributable to taxable temporary differences.

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