CONSOLIDATED STATEMENTS OF CHANGES IN PARTNER'S CAPITAL - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Increase (Decrease) in Partners' Capital
Balance			$ (35,315,177)	$ (34,224,725)
Balance (in units)			124,386	124,409
Distribution to Partners			$ (3,358,443)	$ (3,358,648)
Stock Buyback				(42,548)
Stock Buyback (in units)			(23)
Net income	$ 660,329	$ 871,720	$ 2,592,212	5,249,663
Balance	$ (36,081,408)	$ (32,376,258)	$ (36,081,408)	$ (32,376,258)
Balance (in units)	124,386	124,386	124,386	124,386
Subtotal
Increase (Decrease) in Partners' Capital
Balance (in units)			180,225	180,225
Balance (in units)	180,225	180,225	180,225	180,225
General Partnership
Increase (Decrease) in Partners' Capital
Balance			$ (351,745)	$ (340,840)
Balance (in units)			1,802	1,802
Distribution to Partners			$ (33,584)	$ (33,586)
Stock Buyback				(426)
Net income			25,922	52,497
Balance	$ (359,407)	$ (322,355)	$ (359,407)	$ (322,355)
Balance (in units)	1,802	1,802	1,802	1,802
Treasury Units
Increase (Decrease) in Partners' Capital
Balance (in units)			(55,839)	(55,816)
Stock Buyback (in units)			(23)
Balance (in units)	(55,839)	(55,839)	(55,839)	(55,839)
Class A
Increase (Decrease) in Partners' Capital
Balance			$ (28,280,285)	$ (27,407,924)
Balance (in units)			144,180	144,180
Distribution to Partners			$ (2,686,755)	$ (2,686,919)
Stock Buyback				(34,038)
Net income			2,073,770	4,199,730
Balance	$ (28,893,270)	$ (25,929,151)	$ (28,893,270)	$ (25,929,151)
Balance (in units)	144,180	144,180	144,180	144,180
Class B
Increase (Decrease) in Partners' Capital
Balance			$ (6,683,147)	$ (6,475,961)
Balance (in units)			34,243	34,243
Distribution to Partners			$ (638,104)	$ (638,143)
Stock Buyback				(8,084)
Net income			492,520	997,436
Balance	$ (6,828,731)	$ (6,124,752)	$ (6,828,731)	$ (6,124,752)
Balance (in units)	34,243	34,243	34,243	34,243