|
Fair Value Measurements (Quantitative Information Used As Level 3 Inputs) (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
|
Jun. 30, 2012
|
Jun. 30, 2011
|
Jun. 30, 2012
|
Jun. 30, 2011
|
Dec. 31, 2011
|
|
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Net premiums written | $ 427,630 | $ 427,995 | $ 920,205 | $ 880,570 | |
| Net reserve for claims and claim expenses | 1,801,247 | 1,801,247 | 1,992,354 | ||
|
Significant Unobservable Inputs (Level 3) [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 452,465 | 452,465 | |||
| Other assets and (liabilities). fair value | 34,185 | 34,185 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Corporate [Member] | Discounted Cash Flow Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 17,521 | 17,521 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Corporate [Member] | Discounted Cash Flow Valuation Technique [Member] | Weighted Average or Actual [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Credit spread | 4.60% | ||||
| Illiquidity premium | 1.00% | ||||
| Risk-free rate | 0.20% | ||||
| Dividend rate | 5.90% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Corporate [Member] | Internal Valuation Model Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 10,254 | 10,254 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Fixed maturity investments [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 27,775 | 27,775 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Private equity partnerships [Member] | Net Asset Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 360,268 | 360,268 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Private equity partnerships [Member] | Net Asset Valuation Technique [Member] | Low [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | (19.70%) | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Private equity partnerships [Member] | Net Asset Valuation Technique [Member] | High [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | 12.60% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Private equity partnerships [Member] | Net Asset Valuation Technique [Member] | Weighted Average or Actual [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | (1.40%) | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Senior secured bank loan funds [Member] | Net Asset Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 22,724 | 22,724 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Senior secured bank loan funds [Member] | Net Asset Valuation Technique [Member] | Weighted Average or Actual [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | 0.40% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member] | Net Asset Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 6,243 | 6,243 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member] | Net Asset Valuation Technique [Member] | Low [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | (0.40%) | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member] | Net Asset Valuation Technique [Member] | High [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | 3.00% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Hedge funds [Member] | Net Asset Valuation Technique [Member] | Weighted Average or Actual [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Estimated performance | 1.90% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Miscellaneous other investments [Member] | Discounted Cash Flow Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 1,270 | 1,270 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Miscellaneous other investments [Member] | Discounted Cash Flow Valuation Technique [Member] | Weighted Average or Actual [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Credit spread | 7.40% | ||||
| Illiquidity premium | 1.00% | ||||
| Risk-free rate | 0.50% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Other Investments [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Assets, fair value | 390,505 | 390,505 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Assumed and ceded reinsurance contracts [Member] | Internal Valuation Model Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Other assets and (liabilities). fair value | 9,689 | 9,689 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Assumed and ceded reinsurance contracts [Member] | Internal Valuation Model Valuation Technique [Member] | Low [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Net premiums written | 0 | ||||
| Contract period | 183 days | ||||
| Net reserve for claims and claim expenses | 0 | 0 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Assumed and ceded reinsurance contracts [Member] | Internal Valuation Model Valuation Technique [Member] | High [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Net premiums written | 12,300 | ||||
| Contract period | 365 days | ||||
| Net reserve for claims and claim expenses | 0 | 0 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Weather and energy related derivatives [Member] | Spread Option, Quanto, Black Scholes and Simulation Valuation Techniques [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Other assets and (liabilities). fair value | 9,081 | 9,081 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Weather and energy related derivatives [Member] | Spread Option, Quanto, Black Scholes and Simulation Valuation Techniques [Member] | Low [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Correlation | 0.00% | ||||
| Volatility | 9.40% | ||||
| Commodity curve | 2.62 | ||||
| Weather curve | 19 | ||||
| Counterparty default risk | 0.00% | ||||
|
Significant Unobservable Inputs (Level 3) [Member] | Weather and energy related derivatives [Member] | Spread Option, Quanto, Black Scholes and Simulation Valuation Techniques [Member] | High [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Correlation | 100.00% | ||||
| Volatility | 525.00% | ||||
| Commodity curve | 200 | ||||
| Weather curve | 5,000 | ||||
| Counterparty default risk | 22.50% | ||||
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Significant Unobservable Inputs (Level 3) [Member] | Other [Member] | Internal Valuation Model Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Other assets and (liabilities). fair value | 1,250 | 1,250 | |||
|
Significant Unobservable Inputs (Level 3) [Member] | Other [Member] | Net Asset Valuation Technique [Member]
|
|||||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | |||||
| Other assets and (liabilities). fair value | $ 14,165 | $ 14,165 | |||