Business Segments - Reconciliation of Reveunes, Segment Profits (Losses) and Net Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenues
Segment revenues																	$ 47,089		$ 63,098		$ 35,513
Investment income																	1,242		1,260		979
Other income																	113		98		61
Interest income (expense)																	(12)		0		(9)
Total revenues	13,904	[1]	16,442	[1]	8,177	[1]	9,921	[1]	20,169	[1]	15,099	[1]	6,219	[1]	22,969	[1],[2]	48,444	[1]	64,456	[1]	36,553
Segment profits (losses) and net income (loss)
Segment profits																	3,128		20,874		5,239
Costs and expenses																	(43,961)		(42,224)		(30,274)
Income from operations before equity in earnings of unconsolidated joint ventures																	4,471		22,232		6,270
Equity in earnings (losses)																	2,535		916		541
Income before income tax expense																	7,006		23,148		6,811
Reportable Segment [Member]
Segment profits (losses) and net income (loss)
Segment profits	3,851		6,592		2,799		3,158		10,196		5,690		989		16,276	[2]	16,400	[3]	33,151	[3]	10,851	[3]
Real estate - commercial/industrial [Member]
Revenues
Segment revenues																	9,941		13,746		10,294
Segment profits (losses) and net income (loss)
Segment profits																	(2,330)		525		(241)
Costs and expenses																	(12,271)		(13,221)		(10,535)
Real estate- resort/residential [Member]
Revenues
Segment revenues																	583		16,134		281
Segment profits (losses) and net income (loss)
Segment profits																	(4,178)		12,192		(2,808)
Costs and expenses																	(4,761)		(3,942)		(3,089)
Mineral resources [Member]
Revenues
Segment revenues																	14,012	[4]	12,206	[4]	6,362	[4]
Segment profits (losses) and net income (loss)
Segment profits																	13,678	[4]	11,997	[4]	6,238	[4]
Costs and expenses																	(334)		(209)		(124)
Farming [Member]
Revenues
Segment revenues																	22,553		21,012		18,576
Segment profits (losses) and net income (loss)
Segment profits																	9,230		8,437		7,662
Costs and expenses																	(13,323)		(12,575)		(10,914)
Corporate expenses [Member]
Segment profits (losses) and net income (loss)
Costs and expenses																	$ (13,272)		$ (12,277)		$ (5,612)

[1] Includes investment income and other income.

[2] Includes revenue of $15,750,000 from the sale of conservation easements.

[3] Segment profits are revenues from operations less operating expenses, excluding investment income and expense, corporate expenses, equity in earnings of unconsolidated joint ventures, and income taxes.

[4] During the fourth quarter of 2012, the Company evaluated its operations and determined that an additional segment should be reported, Mineral Resources. Mineral Resources collects royalty income from oil and gas leases, rock and aggregate leases, and from a cement company.