CONSOLIDATED STATEMENTS OF CHANGES IN PARTNER'S CAPITAL - USD ($)	3 Months Ended		6 Months Ended		142 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2019
Increase (Decrease) in Partners' Capital
Balance			$ (37,823,787)	$ (35,624,010)
Balance (in units)			121,978	124,386
Distribution to Partners			$ (2,338,034)	$ (2,352,443)
Stock Buyback			$ (394,031)	$ (3,305,651)	$ (44,718,000)
Stock Buyback (in units)			(222)	(1,995)
Net income	$ 1,465,051	$ 1,764,244	$ 2,833,834	$ 3,264,760
Balance	$ (37,722,018)	$ (38,017,344)	$ (37,722,018)	$ (38,017,344)	$ (38,017,344)
Balance (in units)	121,756	122,391	121,756	122,391	122,391
Subtotal
Increase (Decrease) in Partners' Capital
Balance (in units)			180,225	180,225
Balance (in units)	180,225	180,225	180,225	180,225	180,225
General Partnership
Increase (Decrease) in Partners' Capital
Balance			$ (376,827)	$ (354,833)
Balance (in units)			1,802	1,802
Distribution to Partners			$ (23,380)	$ (23,524)
Stock Buyback			(3,941)	(33,055)
Net income			28,338	32,648
Balance	$ (375,810)	$ (378,764)	$ (375,810)	$ (378,764)	$ (378,764)
Balance (in units)	1,802	1,802	1,802	1,802	1,802
Treasury Units
Increase (Decrease) in Partners' Capital
Balance (in units)			(58,247)	(55,839)
Stock Buyback (in units)			(222)	(1,995)
Balance (in units)	(58,469)	(57,834)	(58,469)	(57,834)	(57,834)
Class A
Increase (Decrease) in Partners' Capital
Balance			$ (30,287,245)	$ (28,527,352)
Balance (in units)			144,180	144,180
Distribution to Partners			$ (1,870,428)	$ (1,881,955)
Stock Buyback			(315,220)	(2,644,552)
Net income			2,267,068	2,611,808
Balance	$ (30,205,825)	$ (30,442,051)	$ (30,205,825)	$ (30,442,051)	$ (30,442,051)
Balance (in units)	144,180	144,180	144,180	144,180	144,180
Class B
Increase (Decrease) in Partners' Capital
Balance			$ (7,159,715)	$ (6,741,825)
Balance (in units)			34,243	34,243
Distribution to Partners			$ (444,226)	$ (446,964)
Stock Buyback			(74,870)	(628,044)
Net income			538,428	620,304
Balance	$ (7,140,383)	$ (7,196,529)	$ (7,140,383)	$ (7,196,529)	$ (7,196,529)
Balance (in units)	34,243	34,243	34,243	34,243	34,243