Debt Financing (Details) (USD $)	Dec. 31, 2014		Sep. 30, 2014	Dec. 31, 2013
TEBS II Facility [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	$ 118,342,000		$ 118,372,000
TEBS II Facility [Member] | Arbors at Hickory Ridge [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	11,450,000		11,450,000
TEBS II Facility [Member] | Copper Gate [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	5,220,000		5,220,000
TEBS II Facility [Member] | The Palms at Premier Park [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	20,152,000		20,152,000
TEB Facility [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	103,516,998			122,536,536
TEB Facility [Member] | Ashley Square [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	5,159,000			5,212,000
TEB Facility [Member] | Bella Vista [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	6,490,000			6,545,000
TEB Facility [Member] | Bent Tree [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,465,000			7,542,000
TEB Facility [Member] | Bridle Ridge [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,655,000			7,715,000
TEB Facility [Member] | Brookstone [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	9,256,001			9,338,603
TEB Facility [Member] | Cross Creek [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	8,422,997			8,497,933
TEB Facility [Member] | Fairmont Oaks [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,266,000			7,355,000
TEB Facility [Member] | Lake Forest [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	8,886,000
TEB Facility [Member] | Lake Forest [Member] | Consolidated VIEs [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value				8,997,000
TEB Facility [Member] | Runnymede [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	10,440,000			10,525,000
TEB Facility [Member] | Southpark [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	13,680,000			13,795,000
TEB Facility [Member] | Woodlynn Village [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	4,390,000			4,426,000
TEB Facility [Member] | Ohio Properties [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	14,407,000	[1]		14,498,000	[1]
TEB Facility [Member] | Lost Creek [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	0			18,090,000
Series A [Member] | TEBS II Facility [Member] | Avistar at Chase Hill [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	10,000,000		10,000,000
Series A [Member] | TEBS II Facility [Member] | Avistar at the Crest [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	9,700,000		9,700,000
Series A [Member] | TEBS II Facility [Member] | Avistar at the Oaks [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	7,800,000		7,800,000
Series A [Member] | TEBS II Facility [Member] | Avistar in 09 [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	6,735,000		6,735,000
Series A [Member] | TEBS II Facility [Member] | Avistar on the Boulevard [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	16,525,000		16,525,000
Series A [Member] | TEBS II Facility [Member] | Avistar on the Hills [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	5,389,000		5,389,000
Series A [Member] | TEBS II Facility [Member] | Greens of Pine Glen [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	8,366,000		8,396,000
Series A [Member] | TEBS II Facility [Member] | Harden Ranch [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	6,960,000		6,960,000
Series A [Member] | TEBS II Facility [Member] | Tyler Park Apartments [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	6,075,000		6,075,000
Series A [Member] | TEBS II Facility [Member] | Westside Village Market [Member] | Available-for-sale Securities [Member]
Debt Instrument [Line Items]
Available for Sale Securities at Par Value	$ 3,970,000		$ 3,970,000

[1] Collateralized by Crescent Village, Post Woods and Willow Bend which are eliminated upon consolidation (Note 3)