Condensed Consolidated Statements of Partners' Capital - USD ($)	Total	General Partner	Number of Units	Beneficial Unit Certificate Holders	Unallocated Deficit of Consolidated VIEs	Noncontrolling Interest	Accumulated Other Comprehensive Income (Loss) [Member]
Stock Issued During Period, Shares, New Issues			9,200,000
Proceeds from Issuance of Common Stock	$ 51,288,699			$ 51,288,699		$ 0	$ 0
Available-for-sale Securities, Gross Realized Gain (Loss)	(2,413,713)	$ (24,137)		(2,389,576)	$ 0		(2,413,713)
Gain (Loss) on Sales of Mortgage Backed Securities (MBS)	259,949	2,599		257,350	0		259,949
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
Distributions paid or accrued	(16,114,398)	(1,051,166)		(15,063,232)	0	0	0
Net income (loss)	9,704,809	989,619		8,970,120	(254,453)	(477)	0
Unrealized Gain (Loss) on Securities	33,756,771	337,568		33,419,203	0	0	33,756,771
Balance at Jun. 30, 2014	284,791,426	323,019		305,190,555	(20,710,349)	(11,799)	16,661,237
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	5,186,544	51,865		5,134,679	0	0	5,186,544
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
Distributions paid or accrued	(16,043,861)	(980,629)		(15,063,232)	0	0	0
Noncontrolling Interest, Period Increase (Decrease)	12,749	0		0	0	12,749	0
Net income (loss)	10,745,170	928,430		9,895,532	(78,212)	(580)	0
Unrealized Gain (Loss) on Securities	(18,264,107)	(182,641)		(18,081,466)	0	0	(18,264,107)
Balance at Jun. 30, 2015	$ 281,481,441	$ 294,434		$ 302,360,501	$ (21,169,668)	$ (3,826)	$ 28,537,897