Other Income (Expense) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Oct. 27, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015
Investment income, net
Interest and dividend income		$ 1,120	$ 1,859	$ 5,509	$ 3,987
Accretion income		639	440	2,184	961
Realized gains (losses) on the sale of investments		5,276	0	5,276	(833)
Other-than-temporary impairment losses		0	(1,295)	0	(1,295)
Total net investment income from available-for-sale securities		7,035	1,004	12,969	2,820
Interest income from investments in special purpose entities		2,050	2,050	6,150	4,067
Interest accrued on notes receivable and other interest		40	313	657	705
Total investment income, net		9,125	3,367	19,776	7,592
Interest expense
Interest expense and amortization of discount and issuance costs for Senior Notes issued by special purpose entity		(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)	0	(7,869)	0
Accretion income from retained interest investments		237	226	674	656
Hunting lease income		172	138	551	623
Other income, net		164	23	342	455
Other, net		135	387	(6,302)	1,734
Total other income		6,385	$ 804	$ 5,077	$ 3,487
Other Income (Expense) [Line Items]
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Minimum				4.90%
Liability For Potential Settlement Of Ongoing SEC Investigation		3,500		$ 3,500		$ 3,500
Legal Fees		$ 500		$ 4,400
Minimum
Other Income (Expense) [Line Items]
Discount Rate On Retained Interest				3.70%
Maximum
Other Income (Expense) [Line Items]
Discount Rate On Retained Interest				11.60%
Subsequent Event
Other Income (Expense) [Line Items]
Litigation Settlement, Amount	$ 2,750