| **Real Estate Sales (Tables)**                                                                                             | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
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| **Discontinued Operations and Disposal Groups [Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures | The Company’s Condensed Consolidated Statements of Operations includes the following amounts related to the Buyer SPE and NFTF for (i) interest income on the time deposit and amortization of the discounts on the U.S. Treasuries and (ii) interest expense for the Senior Notes, amortization of the discount and issuance costs: Three Months Ended  September 30, Nine Months Ended  September 30, 2015 2014 2015 2014Investment income, net$2,050 $2,050 $6,150 $4,067Interest expense $(2,189) $(2,185) $(6,566) $(4,397) |

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| - Definition
Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.
+ References
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