Other Income (Expense) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income (Expense) [Line Items]
Interest and dividend income	$ 6,258,000	$ 1,171,000	$ 0
Accretion income	1,455,000	0	0
Realized (losses) gains on the sale of investments	(833,000)	93,000	0
Other-than-temporary impairment losses	(1,295,000)	0	0
Total net investment income from available-for-sale securities	5,585,000	1,264,000	0
Interest income from investments in special purpose entities	6,116,000	0	0
Interest accrued on notes receivable	990,000	234,000	707,000
Total investment income, net	12,691,000	1,498,000	707,000
Interest expense and amortization of discount and issuance costs for Senior Notes issued by special purpose entity	(6,584,000)	0	0
Interest expense	(2,024,000)	(2,040,000)	(2,820,000)
Total interest expense	(8,608,000)	(2,040,000)	(2,820,000)
Accretion income from retained interest investments	889,000	793,000	(570,000)
Hunting lease income	938,000	1,850,000	2,193,000
Litigation and insurance proceeds received	1,814,000	560,000	1,671,000
Southwest guarantee	0	0	832,000
Other income, net	847,000	1,007,000	2,276,000
Other, net	4,488,000	4,210,000	6,402,000
Total other income	8,571,000	3,668,000	4,289,000
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Minimum	4.90%
Litigation Settlement, Amount	1,800,000		1,700,000
Insurance Proceeds Received		600,000
Promissory Note Received for Sale of Equity Interest in Joint Venture	3,000,000
Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee	$ 600,000
Minimum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate	3.70%
Maximum
Other Income (Expense) [Line Items]
Retained interest, effective interest rate	11.80%