Land and Development Costs and Subsurface Interests - Beachfront Venture (Details) ft² in Millions		3 Months Ended			12 Months Ended
	Nov. 17, 2016 USD ($) a	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) ft² tenant	Dec. 31, 2015 USD ($) a	Dec. 31, 2014 USD ($)
Real Estate Properties [Line Items]
Discount on acquisition of noncontrolling interest					$ 4,778,790
Impairment Charges		$ 1,970,822	$ 209,908	$ 510,041	2,180,730	$ 510,041	$ 421,040
Property, asset total					274,334,139	268,970,875
Impact Fee Credits					925,000	3,100,000
Mitigation Credits					1,400,000	1,400,000
Impact Fee and Mitigation Credits, balance					2,322,906	4,554,227
Cash received for impact fee credits					2,200,000	$ 463,000
6 Acres of Undeveloped Land in Daytona Beach Florida [Member]
Real Estate Properties [Line Items]
Area of a real estate property | a						6
Payment to acquire noncontrolling interest					4,800,000
Discount on acquisition of noncontrolling interest					879,000
Impairment Charges					0
Property, asset total					$ 11,700,000
Additional area density allowable under current zoning | ft²					1.2
Number of tenants | tenant					2
Variable Interest Entity [Member] | 6 Acres of Undeveloped Land in Daytona Beach Florida [Member]
Real Estate Properties [Line Items]
Area of a real estate property | a	6
Payment to acquire noncontrolling interest	$ 4,800,000
Discount on acquisition of noncontrolling interest	$ 879,000