Debt Financing (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	$ 122,835,514		$ 124,648,502
Ashley Square [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	5,224,000		5,260,000
Bella Vista [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	6,545,000		6,600,000
Bent Tree [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,560,000		7,614,000
Bridle Ridge [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,715,000		7,765,000
Brookstone [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	9,358,555		9,416,794
Cross Creek [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	8,515,959		8,568,409
Fairmont Oaks [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,376,000		7,439,000
Lake Forest [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	9,024,000		9,105,000
Runnymede [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	10,565,000		10,605,000
Southpark [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	13,900,000		13,900,000
Woodlynn Village [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	4,443,000		4,460,000
Ohio Properties [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	14,519,000	[1]	14,582,000	[1]
Lost Creek [Member] | Tax-exempt mortgage revenue bonds [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	$ 18,090,000		$ 18,315,000

[1] (1) Collateralized by Crescent Village, Postwoods, and Willow Bend (Note 2 and Note 9)