Quarterly Results (unaudited) (Details) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Quarterly Financial Information [Line Items]
Equity in income of Joint Ventures	$ 970,663		$ (58,561)		$ (54,507)		$ 885,403		$ (4,588)	$ 3,269	$ 79,832	$ 75,814	$ 1,742,998	$ 154,327	$ 720,494
Interest and other income	1,923		3,213		3,108		1,345		1,370	1,326	1,785	3,425	9,589	7,906	11,041
Net income (loss)	929,366		(89,641)		(86,945)		825,229		(43,513)	(37,700)	37,490	21,656	1,578,009	(22,067)	553,476
Class A Limited Partners
Schedule of Quarterly Financial Information [Line Items]
Net income (loss)													421,040	(112,043)	475,159
Net income (loss) allocated to limited partners	496,715		0		0		(75,675)		(43,078)	(37,323)	(110,819)	79,177	421,040	(112,043)	475,159
Net income (loss) per weighted-average limited partner unit (per unit)	0.15		0.00		0.00		(0.02)		(0.01)	(0.01)	(0.03)	0.02	0.13	(0.03)	0.15
Distribution of operating cash to limited partner (per unit)	0.00		0.00		0.00		0.00		0.00	0.00	0.00	0.00
Distribution of net property sale proceeds to limited partner (per unit)	1.09		0.00		0.00		0.00		0.00	0.00	0.99	0.00
Class B Limited Partners
Schedule of Quarterly Financial Information [Line Items]
Net income (loss)													1,157,636	90,196	77,430
Net income (loss) allocated to limited partners	432,651		(89,641)		(86,945)		901,571		0	0	147,934	(57,738)	1,157,636	90,196	77,430
Net income (loss) per weighted-average limited partner unit (per unit)	1.91	[1]	(0.40)	[1]	(0.38)	[1]	3.99	[1]	0.00	0.00	0.65	(0.26)	5.12	0.40	0.33
Distribution of operating cash to limited partner (per unit)	0.00		0.00		0.00		0.00		0.00	0.00	0.00	0.00
Distribution of net property sale proceeds to limited partner (per unit)	0.80		0.00		0.00		0.00		0.00	0.00	1.11	0.00
General Partners
Schedule of Quarterly Financial Information [Line Items]
Net income (loss)													(667)	(220)	887
Net income (loss) allocated to general partners	$ 0		$ 0		$ 0		$ (667)		$ (435)	$ (377)	$ 375	$ 217	$ (667)	$ (220)	$ 887

[1] The quarterly per-unit amounts have been calculated using actual income (loss) for the respective quarters. Conversely, the corresponding annual income (loss) per-unit amounts have been calculated assuming that income (loss) was earned ratably over the year. As a result, the sum of these quarterly per-unit amounts does not equal the respective annual per-unit amount presented in the accompanying financial statements.