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Investments (Number of Securities in an Unrealized Unrecognized Loss Position) (Details) (USD $) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | Dec. 31, 2010
Unrealized Unrecognized Loss | $ 30,311,000 |  |  | $ 30,311,000 |  |  | $ 21,557,000 |
Aggregate unrealized loss position | 23,462,000 | [1] |  | 23,462,000 | [1] |  | 11,572,000 | [1]
Securities In Unrealized Unrecognized Loss Position For More Than Twelve Months Unrealized Unrecognized Loss | 6,800,000 |  |  | 6,800,000 |  |  |  |
Other-than-temporary credit impairment on the third security | 2,543,000 |  | 2,807,000 | 3,342,000 |  | 17,231,000 |  |
Non-credit impariment in OCI on the third security | (150,000) |  | (1,284,000) | 280,000 |  | 905,000 |  |
Structured Securities [Member] |  |  |  |  |  |  |  |
Securities In Unrealized Unrecognized Loss Position For More Than Twelve Months Unrealized Unrecognized Loss | 5,900,000 |  |  | 5,900,000 |  |  |  |
Commercial Mortgage-backed Securities ("CMBS") [Member] |  |  |  |  |  |  |  |
Securities In Unrealized Unrecognized Loss Position For More Than Twelve Months Unrealized Unrecognized Loss | 3,600,000 |  |  | 3,600,000 |  |  |  |
Unrealized unrecognized losses on securities previously impaired | 3,200,000 |  |  | 3,200,000 |  |  |  |
Unrealized unrecognized losses on securities previously impaired number of securities | 3 |  |  | 3 |  |  |  |
Securities with no further impairment | 2 |  |  | 2 |  |  |  |
Commercial Mortgage-backed Securities ("CMBS") [Member] | Previously Impaired Securities With Further Impairment [Member] |  |  |  |  |  |  |  |
Other-than-temporary credit impairment on the third security |  |  |  | 100,000 |  |  |  |
Non-credit impariment in OCI on the third security |  |  |  | 600,000 |  |  |  |
Equity Securities [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 139 |  |  | 139 |  |  |  |
Aggregate unrealized loss position | 18,004,000 | [1] |  | 18,004,000 | [1] |  | 0 | [1]
Fixed Maturity Securities [Member] |  |  |  |  |  |  |  |
Decrease in unrealized/unrecognized losses |  |  |  | 9,300,000 |  |  |  |
Eighty Percent to Ninety-Nine Percent [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 188 |  |  | 188 |  |  | 193 |
Unrealized Unrecognized Loss | 16,142,000 |  |  | 16,142,000 |  |  | 16,310,000 |
Sixty Percent to Seventy-Nine Percent [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 64 |  |  | 64 |  |  | 2 |
Unrealized Unrecognized Loss | 9,554,000 |  |  | 9,554,000 |  |  | 1,125,000 |
Forty Percent to Fifty-Nine Percent [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 11 |  |  | 11 |  |  | 2 |
Unrealized Unrecognized Loss | 2,963,000 |  |  | 2,963,000 |  |  | 2,160,000 |
Twenty Percent to Thirty-Nine Percent [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 3 |  |  | 3 |  |  | 1 |
Unrealized Unrecognized Loss | 1,652,000 |  |  | 1,652,000 |  |  | 986,000 |
Zero Percent to Nineteen Percent [Member] |  |  |  |  |  |  |  |
Number of securities in an unrealized/unrecognized loss position | 0 |  |  | 0 |  |  | 1 |
Unrealized Unrecognized Loss | $ 0 |  |  | $ 0 |  |  | $ 976,000 |
[1] | Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI. In addition, this column includes remaining unrealized gain or loss amounts on securities that were transferred to an HTM designation in the first quarter of 2009 for those securities that are in a net unrealized/unrecognized loss position.

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- Definition This item represents the sum of (i) the excess of amortized cost over fair value for available-for-sale securities that are in a loss position and (ii) the market fluctuations on held-to-maturity securities from the later of (a) the date a security is designated as held-to-maturity; or (b) the date that an other-than-temporary impairment charge is recognized on a held-to-maturity security for securities that are in an unrecognized loss position. + Details
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- Definition This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months for those securities which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 17 -Subparagraph a -Clause 2 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-1 -Paragraph 21 -Subparagraph a -Clause 2 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition The amount of other than temporary impairment (OTTI) loss on a debt security, categorized as either Available-for-sale or Held-to-maturity, related to factors other than credit losses when the entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis. This amount, which includes the portion attributable to the noncontrolling interest, if any, is deducted from the total impairment losses of investments (before taxes) presented on the income statement; this amount is also referred to as the amount incurred by the reporting entity or the consolidated entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15D -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 16B -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 7 -Footnote 2 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 17 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15C -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition The amount of other than temporary impairment (OTTI) losses on equity securities, OTTI related to credit losses on debt securities, and OTTI losses on debt securities when the entity intends to sell the securities or it is more likely than not that the entity will be required to sell the securities before recovery of its amortized cost basis. Additionally, this item includes OTTI losses recognized during the period on investments accounted for under the cost method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 16B -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 7 -Footnote 2 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15C -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 15D -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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