Consolidated Statements of Partners' Capital - USD ($)	Total	General Partner	Limited Partner [Member]	Unallocated Deficit of Consolidated VIEs	Accumulated Other Comprehensive Income (Loss) [Member]	Number of Units	Noncontrolling Interest
Balance at Dec. 31, 2014	$ 309,927,904	$ 578,238	$ 330,457,117	$ (21,091,456)	$ 51,698,418		$ (15,995)
Partners' Capital Account, Units at Dec. 31, 2014						60,252,928
Distributions paid or accrued	(16,043,861)	(980,629)	(15,063,232)
Net income (loss) allocated to Partners
Sale of MF Property	12,749						12,749
Net income (loss)	10,745,170	928,430	9,895,532	(78,212)			(580)
Unrealized gain (loss) on securities	(18,264,107)	(182,641)	(18,081,466)		(18,264,107)
Unrealized gain (loss) on bond purchase commitment	(4,896,414)	(48,964)	(4,847,450)		(4,896,414)
Balance at Jun. 30, 2015	281,481,441	294,434	302,360,501	$ (21,169,668)	28,537,897		(3,826)
Partners' Capital Account, Units at Jun. 30, 2015						60,252,928
Balance at Dec. 31, 2015	313,124,827	399,077	312,720,264		60,963,687		5,486
Partners' Capital Account, Units at Dec. 31, 2015						60,252,928
Reversal of net unrealized gain on sale of securities	(236,439)	(2,364)	(234,075)		(236,439)
Distributions paid or accrued	(17,291,101)	(2,227,869)	(15,063,232)
Net income (loss) allocated to Partners
Net income (loss)	13,410,851	2,189,068	11,221,896				(113)
Unrealized gain (loss) on securities	72,171,756	721,718	71,450,038		72,171,756
Unrealized gain (loss) on bond purchase commitment	11,584,459	115,845	11,468,614		11,584,459
Balance at Jun. 30, 2016	$ 392,764,353	$ 1,195,475	$ 391,563,505		$ 144,483,463		$ 5,373
Partners' Capital Account, Units at Jun. 30, 2016						60,252,928