Segment Reporting (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Net interest margin		$ 17,906	$ 16,334
Property income		68,722	53,274
Fee and other income		2,852	5,594
Provision for losses		1,325	2,000
Depreciation and amortization expense		24,276	19,024
Operating income		(6,240)	(3,247)
Change in fair value of financial instruments		(4,088)	4,490
Income tax benefit (provision)		993	(582)
Net income (loss)		(10,503)	266
Operating Segments | Owning and Management Segment
Segment Reporting Information [Line Items]
Net interest margin		18,171	16,572
Property income		30,056	31,617
Fee and other income		9,725	9,790
Provision for losses		1,325	2,000
Depreciation and amortization expense		12,749	12,986
Operating income		(3,650)	(3,004)
Change in fair value of financial instruments		(4,088)	4,490
Income tax benefit (provision)		993	(582)
Net income (loss)		(9,148)	1,817
Operating Segments | IRT Segment
Segment Reporting Information [Line Items]
Property income		38,666	21,657
Depreciation and amortization expense		11,527	6,038
Operating income		(2,590)	(242)
Net income (loss)		(46)	(241)
Eliminations
Segment Reporting Information [Line Items]
Net interest margin	[1]	(265)	(238)
Fee and other income	[1]	(6,873)	(4,196)
Operating income	[1]		(1)
Net income (loss)	[1]	$ (1,309)	$ (1,310)

[1] The transactions that occur between the reportable segments include advisory and property management services, as well as, providing commercial mortgages on our owned real estate.