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Fair Value of Financial Instruments (Tables) | 6 Months Ended
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Jun. 30, 2015
Financial Instruments, Owned, at Fair Value [Abstract] |
Estimated Fair Values of Financial Instruments | The following table presents the estimated fair values of financial instruments at June 30, 2015 and December 31, 2014:
| June 30, 2015 |  | December 31, 2014
| (Amounts in thousands)
Assets |  |  |
Investments | $ | 3,359,767 |  |  | $ | 3,403,822 |
Liabilities |  |  |
Options sold | $ | 51 |  |  | $ | 194 |
Total return swaps | $ | 1,564 |  |  | $ | 4,025 |
Secured notes | $ | 140,000 |  |  | $ | 140,000 |
Unsecured note | $ | 150,000 |  |  | $ | 150,000 |

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