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Investments - Additional Information (Detail) (USD $) | 9 Months Ended |
--- | --- | ---
Sep. 30, 2012 Security | Dec. 31, 2011
Investments [Line Items] |  |
Percentage of future claim payments made in cash | 25.00% |
Percentage of future claim payments made in surplus note | 75.00% |
12 Months or Longer, Gross Unrealized Loss | $ 80,767,000 | $ 114,011,000
Unrealized losses of one security under closed-block life insurance issuance | 2,879,000 |
Unrealized losses of one security of large diversified financial services company | 3,846 |
Period of unrealized loss position on large diversified financial services company | 63 months |
Unrealized loss position of Alt-A securities greater than twelve months | 23,867,000 |
Percentage of unrealized losses on mortgage-backed securities attributable to Alt-A Securities | 99.90% |
Number of individual Alt-A securities | 17 |
Unrealized losses on security secured by IRS facility lease payments | 30,747,000 |
Percentage of permitted policy claim | 25.00% |
Securities fair value | 7,065,000 | 7,132,000
Securities fair value | 194,172,000 | 172,880,000
Minimum [Member] |  |
Investments [Line Items] |  |
Period of unrealized loss position on closed-block life insurance Issuance | 39 months |
Period of unrealized loss position on security secured by IRS facility lease payments | 16 months |
Maximum [Member] |  |
Investments [Line Items] |  |
Period of unrealized loss position on closed-block life insurance Issuance | 57 months |
Period of unrealized loss position on security secured by IRS facility lease payments | 57 months |
Below Investment Grade Securities And Non Rated Securities [Member] |  |
Investments [Line Items] |  |
Fair value of below investment grade securities and non-rated securities | 242,028,000 | 268,633,000
Gross Unrealized loss | 56,568,000 | 77,947,000
Other Asset-backed Securities [Member] |  |
Investments [Line Items] |  |
12 Months or Longer, Gross Unrealized Loss | 47,745,000 |
Residential Mortgage-backed securities [Member] |  |
Investments [Line Items] |  |
12 Months or Longer, Gross Unrealized Loss | 23,878,000 | 43,321,000
Corporate Obligations [Member] |  |
Investments [Line Items] |  |
12 Months or Longer, Gross Unrealized Loss | $ 8,541,000 | $ 16,983,000

X
- Definition Number of months closed block life insurance issuance in a continuous unrealized loss position. + References No definition available. + Details
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- Definition Number of months an issuance of a large diversified financial services company that is in a continuous unrealized loss position. + References No definition available. + Details
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- Definition Number of months a security that is secured by IRS facility lease payments is in a continuous unrealized loss position. + References No definition available. + Details
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- Definition Aggregate losses for a closed block life insurance issuance in a continuous unrealized loss position for twelve months or longer. + References No definition available. + Details
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- Definition Aggregate losses for an issuance of a large diversified financial services company that is in a continuous unrealized loss position for twelve months or longer. + References No definition available. + Details
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- Definition Aggregate losses for Alt-A securities that are in a continuous unrealized loss position for twelve months or longer. + References No definition available. + Details
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- Definition Number of Alt-A securities in a continuous unrealized loss position greater than twelve months. + References No definition available. + Details
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- Definition Percentage of unrealized losses on mortgage-backed securities attributable to Alt-A securities. + References No definition available. + Details
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- Definition Aggregate losses for related to a security that is secured by IRS facility lease payments in a continuous unrealized loss position for twelve months or longer. + References No definition available. + Details
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- Definition Aggregate losses of below investment grade securities and non rated securities in a continuous unrealized loss position. + References No definition available. + Details
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- Definition Fair value of securities deposited with governmental authorities. + References No definition available. + Details
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- Details
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- Definition Percentage of claim permitted to be paid. + References No definition available. + Details
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- Definition Percentage of future claim payments in cash. + References No definition available. + Details
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- Definition Fair Value of securities held to collateralize and fund repayment of debt issued through a resecuritization transaction. + References No definition available. + Details
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- Definition Amount of the excess of amortized cost basis over fair value of securities that have been in a loss position for twelve months or longer for securities which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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