Impairment of Long-Lived Assets - Additional Information (Details)				3 Months Ended									4 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 16, 2016 USD ($)	Apr. 17, 2015 USD ($)	Dec. 31, 2016 USD ($) a	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($) a	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) a	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($) property	Sep. 30, 2014 USD ($)	Dec. 31, 2016 USD ($) a	Dec. 31, 2016 USD ($) a $ / a	Dec. 31, 2015 USD ($) a $ / a	Dec. 31, 2014 USD ($) a $ / a
Property Plant And Equipment [Line Items]
Impairment Charges						$ 1,970,822	$ 209,908				$ 510,041			$ 2,180,730	$ 510,041	$ 421,040
Gain (Loss) from sale of land				$ (83,668)	$ 11,479,490	$ 1,362,948		$ 1,735,115	$ 3,763,140	$ 12,749	5,440			$ 12,758,770	5,516,444	1,500
Land [Member]
Property Plant And Equipment [Line Items]
Impairment Charges															$ 0	0
Gain (Loss) recognized																$ 4,802,000
Area of Real Estate Property | a				9,800									9,800	9,800		99.7
Sales price																$ 8,807,000
Sales price per acre | $ / a																88,000
6 Acres of Undeveloped Land in Daytona Beach Florida [Member]
Property Plant And Equipment [Line Items]
Impairment Charges														$ 0
Area of land | a						6
Area of Real Estate Property | a								6							6
6 Acres of Undeveloped Land in Daytona Beach Florida [Member] | Land [Member]
Property Plant And Equipment [Line Items]
Impairment Charges														0
2016 Disposals | Sold
Property Plant And Equipment [Line Items]
Sales price				$ 74,300,000									$ 74,300,000	74,300,000
2016 Disposals | Sold | Land [Member]
Property Plant And Equipment [Line Items]
Gain (Loss) recognized														$ 8,304,000
Area of Real Estate Property | a				707.7									707.7	707.7
Sales price				$ 13,759,000									$ 13,759,000	$ 13,759,000
Sales price per acre | $ / a														19,000
2016 Disposals | Under contract to be sold | 6 Acres of Undeveloped Land in Daytona Beach Florida [Member]
Property Plant And Equipment [Line Items]
Impairment Charges						$ 717,000
Gain (Loss) from sale of land														$ (646,000)
Estimated closing costs														71,000
Area of land impairment charges recognized | a						4
2016 Disposals | Under contract to be sold | 4 Acres of Undeveloped Land in Daytona Beach Florida [Member]
Property Plant And Equipment [Line Items]
Impairment Charges						$ 311,000
Gain (Loss) from sale of land														(256,000)
Estimated closing costs														$ 55,000
Area of land | a						4
Portfolio Sale | Sold
Property Plant And Equipment [Line Items]
Gain (Loss) recognized		$ 11,100,000		$ (82,000)									$ 11,000,000
Sales price		$ 51,600,000
2015 Disposals | Sold
Property Plant And Equipment [Line Items]
Impairment Charges															$ 510,000
Gain (Loss) recognized			$ (497,000)							$ 13,000
Sales price								$ 24,300,000							24,300,000
2015 Disposals | Sold | Land [Member]
Property Plant And Equipment [Line Items]
Gain (Loss) recognized															$ 8,477,000
Area of Real Estate Property | a								114.10							114.10
Sales price								$ 22,529,000							$ 22,529,000
Sales price per acre | $ / a															197,000
2015 Disposals | Under contract to be sold
Property Plant And Equipment [Line Items]
Impairment Charges											$ 510,000
Number of income properties held for sales | property											2
Gain (Loss) recognized											$ (277,000)
Estimated closing costs											$ 233,000
2014 Disposals | Sold
Property Plant And Equipment [Line Items]
Impairment Charges																$ 421,000
Gain (Loss) recognized												$ (228,000)
Estimated closing costs												$ 193,000
PNC Bank, N.A. | 2016 Disposals | Sold | Altamonte Springs Florida
Property Plant And Equipment [Line Items]
Impairment Charges						$ 942,000
Gain (Loss) from sale of land	$ (922,000)
Gain (Loss) recognized					20,000
Sales price	$ 3,000,000				$ 3,000,000
PNC Bank, N.A. | 2016 Disposals | Under contract to be sold | Altamonte Springs Florida
Property Plant And Equipment [Line Items]
Impairment Charges						$ 942,000