TREASURY UNITS (Details) (USD $)	0 Months Ended		12 Months Ended		64 Months Ended				3 Months Ended	0 Months Ended	12 Months Ended		64 Months Ended			0 Months Ended	12 Months Ended		64 Months Ended	3 Months Ended			0 Months Ended	12 Months Ended		64 Months Ended	3 Months Ended
	Aug. 08, 2008	Aug. 20, 2007	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2012	Mar. 06, 2008	Jan. 30, 2008	Jan. 15, 2008	Mar. 31, 2013 Subsequent event	Sep. 17, 2008 Class A Treasury Units	Dec. 31, 2012 Class A Treasury Units	Dec. 31, 2010 Class A Treasury Units	Dec. 31, 2012 Class A Treasury Units	Jan. 03, 2012 Class A Treasury Units	Aug. 20, 2007 Class A Treasury Units	Sep. 17, 2008 Class B Treasury Units	Dec. 31, 2012 Class B Treasury Units	Dec. 31, 2010 Class B Treasury Units	Dec. 31, 2012 Class B Treasury Units	Mar. 31, 2013 Class B Treasury Units Subsequent event	Dec. 31, 2012 Class B Treasury Units Harold Brown, the treasurer of the General Partner	Dec. 31, 2012 Class B Treasury Units Ronald Brown, the president of the General Partner	Sep. 17, 2008 General Partnership	Dec. 31, 2012 General Partnership	Dec. 31, 2010 General Partnership	Dec. 31, 2012 General Partnership	Mar. 31, 2013 General Partnership Subsequent event	Dec. 31, 2012 General Partnership Harold Brown, the treasurer of the General Partner	Dec. 31, 2012 General Partnership Ronald Brown, the president of the General Partner
Treasury units (in shares)			49,781		49,781						39,825		39,825				9,458		9,458					498		498
Period for repurchase of depository receipts	12 months	12 months
Depository receipts authorized to be repurchased (in shares)		300,000				1,500,000	900,000	600,000
Number of units in each depository receipt														0.03333	0.1
Fixed distribution percentage of unit holders											80.00%						19.00%							1.00%
Repurchase of depository receipts (in shares)			24,967	20,688	1,219,927				9,709									164	1,921					10	9	101
Repurchase price of depository receipts (in dollars per share)					$ 24.62				$ 32.24
Repurchase price of units (in dollars per share)									$ 967.20				$ 738.60						$ 613.94	$ 967.20						$ 613.94	$ 967.20
Repurchase of units (in shares)			(1,040)	(862)												6,309	198			76.86			333				4.05
Repurchase of units			$ 906,214	$ 540,911	$ 31,386,000				$ 321,240		$ 726,058	$ 432,920					$ 171,148	$ 102,591		$ 74,335				$ 9,008	$ 5,400		$ 3,912
Issuance of treasury units (in shares)										6,642
Percentage of units owned by partners																					75.00%	25.00%						75.00%	25.00%
Repurchase of depository receipts			$ 726,058