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Fair Value of Financial Instruments (Estimated Fair Values Of Financial Instruments) (Details) - USD ($) | Jun. 30, 2015 | Dec. 31, 2014
--- | --- | ---
Liabilities |  |
Total return swap | $ 1,564,000 | $ 4,025,000
Unsecured Debt | 150,000,000 | 150,000,000
Equity Contract [Member] |  |
Liabilities |  |
Equity contracts | 51,000 | 194,000
Investments [Member] |  |
Assets |  |
Investments | 3,359,767,000 | 3,403,822,000
Secured Notes [Member] |  |
Liabilities |  |
Secured notes payable | $ 140,000,000 | $ 140,000,000

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