REAL ESTATE PROPERTIES (Details 2) (USD $)	12 Months Ended					12 Months Ended				2 Months Ended			0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	0 Months Ended	2 Months Ended	0 Months Ended	2 Months Ended	0 Months Ended	2 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Shopping centers/Retail Partnership Yonkers, New York sqft	Sep. 30, 2012 Commercial Primary beneficiary RBH-TRB Newark Holdings LLC	Sep. 30, 2012 Commercial Primary beneficiary RBH-TRB Newark Holdings LLC Mortgages Payable	Sep. 30, 2012 Commercial Primary beneficiary RBH-TRB Newark Holdings LLC Operating and development properties, Newark, New Jersey sqft	Sep. 30, 2011 Commercial Primary beneficiary RBH-TRB Newark Holdings LLC Operating and development properties, Newark, New Jersey	Sep. 30, 2012 Multi Family	Sep. 30, 2012 Multi Family Primary beneficiary item	Nov. 30, 2012 Multi Family Primary beneficiary Subsequent event Purchase of properties item	Nov. 30, 2012 Multi Family Primary beneficiary Minimum Subsequent event Purchase of properties	Nov. 30, 2012 Multi Family Primary beneficiary Maximum Subsequent event Purchase of properties	Mar. 22, 2012 Multi Family Primary beneficiary Palm Beach Gardens, Florida item	Sep. 30, 2012 Multi Family Primary beneficiary Palm Beach Gardens, Florida	Mar. 30, 2012 Multi Family Primary beneficiary Melbourne, Florida item	Sep. 30, 2012 Multi Family Primary beneficiary Melbourne, Florida	Jun. 20, 2012 Multi Family Primary beneficiary Collierville, Tennessee item	Sep. 30, 2012 Multi Family Primary beneficiary Collierville, Tennessee	Jan. 12, 2012 Multi Family Primary beneficiary Marietta, GA item	Sep. 30, 2012 Multi Family Primary beneficiary Marietta, GA	Feb. 23, 2012 Multi Family Primary beneficiary Lawrenceville, GA item	Sep. 30, 2012 Multi Family Primary beneficiary Lawrenceville, GA	Oct. 04, 2012 Multi Family Primary beneficiary North Charleston, SC Subsequent event Purchase of properties	Nov. 30, 2012 Multi Family Primary beneficiary North Charleston, SC Subsequent event Purchase of properties item	Nov. 15, 2012 Multi Family Primary beneficiary Cordova, TN Subsequent event Purchase of properties	Nov. 30, 2012 Multi Family Primary beneficiary Cordova, TN Subsequent event Purchase of properties item	Nov. 19, 2012 Multi Family Primary beneficiary Decatur, GA Subsequent event Purchase of properties	Nov. 30, 2012 Multi Family Primary beneficiary Decatur, GA Subsequent event Purchase of properties item	Sep. 30, 2012 Land Daytona Beach, Florida acre
Real Estate Properties
Area of real estate properties (in square feet)			28,500			690,000
Area of real estate property under construction (in square feet)						252,000
Blanket mortgage on assets					$ 20,100,000
BRT Equity	275,000	4,045,000				4,157,000	3,194,000		28,580,000	14,026,000			14,480,000		3,120,000		6,220,000		2,560,000		2,200,000			4,410,000		6,220,000		3,396,000
Distribution received from partnership						1,170,000
Number of units in multi-family residential property									1,452	884			542		208		325		207		170			208		464		212
Contract Purchase price	116,759,000	2,315,000		1,659,000				115,100,000	115,100,000	57,450,000			59,400,000		9,250,000		32,100,000		8,100,000		6,250,000			21,500,000		25,500,000		10,450,000
Acquisition costs									2,407,000				1,561,000		231,000		615,000
Interest in joint venture (as a percent)			85.00%								80.00%	90.00%		80.00%		80.00%		80.00%		80.00%		80.00%
Acquisition Mortgage debt	169,284,000								89,747,000	45,526,000			45,200,000		7,680,000		25,680,000		6,500,000		4,687,000			17,716,000		19,250,000		8,560,000
Estimated Acquisition Costs										$ 793,000													$ 213,000		$ 388,000		$ 192,000
Area of development parcel (in acres)																													8.9