| **Other Income (Expense) (Tables)**      | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
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| **Other Income and Expenses [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Schedule of other income (expense)       | Other income (expense) consists of the following:  Three Months Ended September 30, Nine Months Ended September 30,  2015 2014 2015 2014Investment income, net        Net investment income from available-for-sale securities        Interest and dividend income $1,120 $1,859 $5,509 $3,987Accretion income 639 440 2,184 961Realized gains (losses) on the sale of investments 5,276 — 5,276 (833)Other-than-temporary impairment losses — (1,295) — (1,295)Total net investment income from available-for-sale securities 7,035 1,00412,969 2,820Interest income from investments in special purpose entities (Note 5) 2,050 2,050 6,150 4,067Interest accrued on notes receivable and other interest 40 313 657 705Total investment income, net 9,125 3,36719,776 7,592Interest expense        Interest expense and amortization of discount and issuance costs for Senior Notes issued by special purpose entity (Note 5) (2,189) (2,185) (6,566) (4,397)Interest expense (686) (765) (1,831) (1,442)Total interest expense (2,875) (2,950)(8,397)(5,839)Other, net        Fees and expenses for the SEC investigation (438) — (7,869) —Accretion income from retained interest investments 237 226 674 656Hunting lease income 172 138 551 623Other income, net 164 23 342 455Other, net 135 387(6,302)1,734         Total other income $6,385 $804$5,077$3,487 |

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| - Definition
Tabular disclosure of the components of non-operating income or non-operating expense that may include amounts earned from dividends, interest on securities, gains (losses) on securities sold, equity earnings of unconsolidated affiliates, net gain (loss) on sales of business, interest expense and other miscellaneous income or expense items.
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