Consolidated Statements of Partners' Capital - USD ($)	Total	General Partner [Member]	Beneficial Unit Certificate Holders - Restricted and Unrestricted [Member]	Unallocated Deficit of Consolidated VIEs [Member]	Number of Units - Restricted and Unrestricted [Member]	Noncontrolling Interest [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2013	$ 203,122,765	$ 16,671	$ 223,573,312	$ (20,455,896)		$ (11,322)	$ (20,128,314)
Partners' Capital Account, Units at Dec. 31, 2013					51,052,928
Sale of beneficial certificates, value	51,288,699		51,288,699
Sale of beneficial certificates, unit					9,200,000
Available-for-sale Securities, Gross Realized Gain (Loss)	(2,413,713)	(24,137)	(2,389,576)				(2,413,713)
Gain (Loss) on Sales of Mortgage Backed Securities (MBS)	755,547	7,555	747,992				755,547
Distributions paid or accrued:
Regular distribution	(27,591,056)	(275,910)	(27,315,146)
Distribution of Tier 2 earnings (Note 3)	(3,748,424)	(937,106)	(2,811,318)
Net income (loss)	15,029,188	1,056,316	14,613,105	(635,560)		(4,673)
Unrealized gain (loss) on securities	62,852,308	628,523	62,223,785				62,852,308
Unrealized gain (loss) on bond purchase commitment	10,632,590	106,326	10,526,264				10,632,590
Balance at Dec. 31, 2014	309,927,904	578,238	330,457,117	(21,091,456)		(15,995)	51,698,418
Partners' Capital Account, Units at Dec. 31, 2014					60,252,928
Sale of MF Property	24,282					24,282
Deconsolidation of VIEs		(173,701)	(17,196,359)	17,370,059
Available-for-sale Securities, Gross Realized Gain (Loss)	(630,919)	(6,309)	(624,610)				(630,919)
Distributions paid or accrued:
Regular distribution	(23,343,025)	(233,430)	(23,109,595)
Distribution of Tier 2 earnings (Note 3)	(9,355,825)	(2,338,956)	(7,016,869)
Net income (loss)	26,606,222	2,474,274	20,413,352	$ 3,721,397		(2,801)
Unrealized gain (loss) on securities	10,042,241	100,422	9,941,819				10,042,241
Unrealized gain (loss) on bond purchase commitment	(146,053)	(1,461)	(144,592)				(146,053)
Balance at Dec. 31, 2015	313,124,827	399,077	312,720,264			5,486	60,963,687
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:
Regular distribution	(21,764,612)	(217,646)	(21,546,966)
Distribution of Tier 2 earnings (Note 3)	(11,434,599)	(2,858,650)	(8,575,949)
Net income (loss)	23,200,277	2,992,106	20,208,994			(823)
Repurchase of Beneficial Unit Certificates	(1,603,658)		(1,603,658)
Repurchase of Beneficial Unit Certificates, Units					(272,307)
Restricted units awarded					272,307
Restricted units compensation expense	833,142	8,331	824,811
Beneficial Unit Certificates surrendered to pay tax withholding on vested restricted units					(28,390)
Beneficial unit certificates surrendered to pay tax withholding on vested restricted units, values	(153,306)		(153,306)
Unrealized gain (loss) on securities	(18,596,853)	(185,969)	(18,410,884)				(18,596,853)
Unrealized gain (loss) on bond purchase commitment	(3,234,911)	(32,349)	(3,202,562)				(3,234,911)
Balance at Dec. 31, 2016	$ 280,133,868	$ 102,536	$ 280,026,669			$ 4,663	$ 38,895,484
Partners' Capital Account, Units at Dec. 31, 2016					60,224,538