Investments in Real Estate - Real Estate by Property Type and Segment (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Real Estate Properties [Line Items]
Development property	$ 163,024,000		$ 163,024,000		$ 161,252,000
Operating property	218,311,000		218,311,000		216,416,000
Less: Accumulated depreciation	68,327,000		68,327,000		64,069,000
Total operating property, net	149,984,000		149,984,000		152,347,000
Investment in real estate, net	313,008,000		313,008,000		313,599,000
Capitalized indirect costs incurred	0	$ 100,000	0	$ 200,000
Residential real estate
Real Estate Properties [Line Items]
Development property	99,545,000		99,545,000		99,413,000
Operating property	8,091,000		8,091,000		8,091,000
Commercial real estate
Real Estate Properties [Line Items]
Development property	57,248,000		57,248,000		56,587,000
Resorts and leisure
Real Estate Properties [Line Items]
Development property	214,000		214,000		0
Operating property	109,346,000		109,346,000		109,425,000
Leasing operations
Real Estate Properties [Line Items]
Development property	1,119,000		1,119,000		360,000
Operating property	81,307,000		81,307,000		79,550,000
Forestry
Real Estate Properties [Line Items]
Development property	2,509,000		2,509,000		2,681,000
Operating property	19,517,000		19,517,000		19,300,000
Other
Real Estate Properties [Line Items]
Operating property	50,000		50,000		50,000
Corporate
Real Estate Properties [Line Items]
Development property	$ 2,389,000		$ 2,389,000		$ 2,211,000