Consolidated Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income		$ 30,662,851	$ 23,783,684	$ 26,606,222
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		5,212,859	6,862,530	6,505,011
Provision for loan loss	[1]	295,000
Gain on sale of real estate assets, net		(17,753,303)	(14,072,317)	(4,599,109)
Gain on the sale of discontinued operations				(3,212,447)
Contingent interest realized on investing activities		(2,927,948)	(1,379,466)	(4,756,716)
Note interest income realized from the sale of Fairmont Oaks, Consolidated VIE				(1,454,621)
Gain on sale of securities			(8,097)
Impairment of securities		761,960
Loss (gain) on derivatives, net of cash paid		(170,031)	(17,618)	1,802,655
Restricted unit compensation expense		1,615,242	833,142
Bond premium/discount amortization		(320,382)	(153,922)	238,996
Amortization of deferred financing costs		2,324,535	1,862,509	1,622,789
Deferred income tax expense (benefit)		(400,000)	366,000
Change in preferred return receivable from unconsolidated entities		(2,922,158)	(718,701)
Changes in operating assets and liabilities, net of effect of acquisitions
(Increase) decrease in interest receivable		442,071	(1,762,344)	(2,452,084)
(Increase) decrease in other assets		245,564	(112,174)	(416,419)
Decrease in accounts payable and accrued expenses		73,267	(251,695)	(496,859)
Net cash provided by operating activities		17,139,527	15,231,531	19,387,418
Cash flows from investing activities:
Capital expenditures		(441,790)	(635,739)	(3,282,107)
Restructure and acquisition of interest rate derivative				(562,088)
Proceeds from sale of MF Properties		46,525,000	45,850,000	16,196,510
Proceeds from sale of land held for development		3,000,000
Proceeds from sale of discontinued operations				22,900,000
Proceeds from sale of mortgage revenue bond			9,295,000
Proceeds from the sale of MBS Securities			14,997,069
Cash realized from the bond exchange for the Suites on Paseo property				514,095
Acquisition of mortgage revenue bonds		(121,347,000)	(130,620,000)	(188,572,000)
Contributions to unconsolidated entities		(14,096,478)	(18,751,305)
Acquisition of MF Property			(9,882,800)
Restricted cash - debt collateral paid		(1,043,283)	(2,564,000)	(4,815,000)
Restricted cash - debt collateral released		5,038,371	4,429,019	7,522,959
Increase (decrease) in restricted cash		776,981	342,609	(16,004)
Acquisition of taxable mortgage revenue bonds				(500,000)
Principal payments received on taxable mortgage revenue bonds		1,565,455	551,162	153,821
Cash paid for land held for development and deposits on potential purchases		(381,066)	(100,000)	(2,889,400)
Advances on property loans		(2,712,816)	(8,414,215)	(11,208,763)
Principal payments received on property loans		2,667,276	2,806,056	2,958,415
Net cash used in investing activities		(21,505,164)	(83,052,386)	(138,703,473)
Cash flows from financing activities:
Distributions paid		(33,465,038)	(34,245,664)	(31,556,898)
Proceeds from the sale of redeemable Series A Preferred Units		53,631,000	40,869,000
Payment of offering costs related to the sale of redeemable Series A Preferred Units		(8,875)	(86,814)
Acquisition of interest rate derivatives		(556,017)
Repurchase of Beneficial Unit Certificates		(1,466,222)	(1,603,658)
Proceeds from the sale of Beneficial Unit Certificates		978,628
Payment of offering costs related to the sale of Beneficial Unit Certificates		(101,143)
Payment of tax withholding related to restricted unit awards		(400,607)
Distribution to noncontrolling interest		(76,316)
Proceeds from debt financing		144,100,000	173,302,645	293,205,000
Principal payments on debt financing		(81,773,730)	(129,465,032)	(182,132,712)
Principal payments on other secured financing			(7,500,000)
Principal borrowing on mortgages payable			7,500,000
Principal payments on mortgages payable		(15,952,005)	(17,997,186)	(8,415,981)
Principal borrowing on unsecured lines of credit		80,560,000	87,487,639	74,071,261
Principal payments on unsecured and secured lines of credit		(90,560,000)	(44,984,639)	(55,149,000)
Decrease in security deposit liability related to restricted cash		(227,029)	(44,984)	16,004
Deferred costs related to future equity raises				(169,667)
Debt financing and other deferred costs		(1,467,831)	(1,697,713)	(2,709,513)
Net cash provided by financing activities		53,214,815	71,533,594	87,158,494
Net increase (decrease) in cash and cash equivalents		48,849,178	3,712,739	(32,157,561)
Cash and cash equivalents at beginning of period		20,748,521	17,035,782	49,193,343
Cash and cash equivalents at end of period		69,597,699	20,748,521	17,035,782
Supplemental disclosure of cash flow information:
Cash paid during the period for interest		21,558,593	15,175,628	12,866,079
Cash paid during the period for income taxes		5,890,835	4,615,000
Supplemental disclosure of noncash investing and financing activities:
Distributions declared but not paid for Beneficial Unit Certificates and general partner		8,423,803	8,017,950	8,759,343
Distributions declared but not paid for Series A Preferred Units		692,917	271,518
Land contributed as investment in an unconsolidated entity		3,091,023
Capital expenditures financed through accounts payable		72,390	46,528	26,368
Deferred financing and equity issuance costs financed through accounts payable		90,339	234,372
Liabilities assumed in the acquisition of MF Property			135,326
Beneficial Unit Certificates surrendered for tax withholding liabilities on restricted units			153,306
Exchange of Suites on Paseo assets held for the Suites on Paseo property				42,665,912
Public housing capital fund trusts [Member]
Cash flows from investing activities:
Principal payments received		5,979,738	2,014,120	963,526
Mortgage Revenue Bonds [Member]
Cash flows from investing activities:
Principal payments received		$ 52,964,448	$ 7,630,638	$ 21,932,563

[1] See table below for a summary of terms for the individual Term A/B Trust securitizations. Activity for the year ended December 31, 2017 consists of the reversal of $55,000 allowance for loan loss related to Lake Forest and the increase of $350,000 allowance for loan loss related to Ashley Square. The net provision for loan loss for the year ended December 31, 2017 is recorded as a reduction to other interest income on the consolidated statements of operations.