v2.4.0.8

Fair Value Measurements - Fair Value Hierarchy (Details) (USD $) In Thousands, unless otherwise specified |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 Months Ended
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Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 Investments in limited partnerships [Member] | Dec. 31, 2013 Investments in limited partnerships [Member] | Mar. 31, 2014 Other [Member] | Dec. 31, 2013 Other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. treasury bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. treasury bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. agency bonds – mortgage-backed [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. agency bonds – mortgage-backed [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. agency bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] U.S. agency bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Non-U.S. government bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Non-U.S. government bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Other mortgage-backed securities [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Other mortgage-backed securities [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Municipal bonds – auction rate [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Municipal bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Municipal bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. treasury bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. treasury bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. agency bonds – mortgage-backed [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. agency bonds – mortgage-backed [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. agency bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] U.S. agency bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Non-U.S. government bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Non-U.S. government bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Other mortgage-backed securities [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Other mortgage-backed securities [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Municipal bonds – auction rate [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Municipal bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Other Observable Inputs (Level 2) [Member] Municipal bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. treasury bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. treasury bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. agency bonds – mortgage-backed [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. agency bonds – mortgage-backed [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. agency bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] U.S. agency bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Non-U.S. government bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Non-U.S. government bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Other mortgage-backed securities [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Other mortgage-backed securities [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Municipal bonds – auction rate [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Municipal bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Significant Unobservable Inputs (Level 3) [Member] Municipal bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Fixed Maturities [Member] securities | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Fixed Maturities [Member] securities | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. treasury bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. treasury bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. agency bonds – mortgage-backed [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. agency bonds – mortgage-backed [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. agency bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] U.S. agency bonds – other [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Non-U.S. government bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Non-U.S. government bonds [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Other mortgage-backed securities [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Other mortgage-backed securities [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Corporate bonds [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Municipal bonds – auction rate [Member] | Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Municipal bonds – other [Member] | Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Total Fair Value [Member] Municipal bonds – other [Member] | Jan. 15, 2014 Junior subordinated debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Extinguishment of debt, amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 126,381
Fixed maturities, fair value |  |  |  |  |  |  |  |  | 17,135 | 17,209 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |  |  | 0 | 0 | 1,235,470 | 1,262,655 | 8,196 | 8,108 | 73,965 | 73,212 | 44,368 | 33,444 | 1,725,768 | 1,606,700 | 99,170 | 63,917 | 61,569 |  |  | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |  |  |  |  | 17,135 | 17,209 | 1,235,470 | 1,262,655 | 8,196 | 8,108 | 73,965 | 73,212 | 44,368 | 33,444 | 1,725,768 | 1,606,700 | 99,170 | 63,917 | 61,569 |
Other investments, fair value |  |  |  |  |  |  | 0 | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,773 | 5,092 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,773 | 5,092 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total |  |  |  |  |  |  | 17,135 | 17,209 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,151,684 | 3,144,858 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,773 | 5,092 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,174,592 | 3,167,159 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of total assets |  |  |  |  |  |  | 0.40% | 0.40% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 64.70% | 66.70% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.10% | 0.10% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 65.20% | 67.20% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets, valued by third party, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 99.90% | 95.30% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets, valued using market approach, percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.10% | 4.70% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets, valued using market approach, number |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 | 5 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets, valued using market approach, amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,411 | 150,298 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other investments | $ 5,773 | $ 5,092 | $ 4,773 | $ 4,092 | $ 1,000 | $ 1,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other investments, percent of assets |  |  | 0.20% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + Details
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition Other investments not otherwise specified in the taxonomy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph g -Article 7 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(f,g)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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