Assets and Liabilities of Consolidated Variable Interest Entities (Detail) - USD ($) $ in Thousands		Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Investments in mortgages and loans, at amortized cost:
Commercial mortgages, mezzanine loans, other loans and preferred equity interests		$ 1,495,343		$ 1,623,583
Allowance for loan losses		(18,237)	$ (18,165)	(17,097)	$ (12,796)	$ (10,797)	$ (9,218)
Total investment in mortgages and loans, net (including $1,272,536 and $1,428,961 held by consolidated VIEs, respectively)		1,477,106		1,606,486
Investments in real estate
Investments in real estate		2,409,139		2,517,645
Accumulated depreciation	[1]	(209,096)		(198,326)
Total investments in real estate		2,200,043		2,319,319
Cash and cash equivalents		66,885		125,886	$ 104,772		$ 121,726
Restricted cash		159,429		213,012
Accrued interest receivable		42,139		47,343
Other assets		68,794		71,207
Intangible assets
Accumulated amortization		(34,876)		(26,307)
Total intangible assets		25,668		32,675
Total assets		4,040,064		4,415,928
Liabilities and Equity
Accrued interest payable		11,102		9,834
Accounts payable and accrued expenses		32,483		39,672
Derivative liabilities		3,972		4,727
Deferred taxes, borrowers’ escrows and other liabilities		182,324		203,477
Total liabilities		3,235,140		3,585,792
Shareholders’ equity:
Accumulated other comprehensive income (loss)		(972)		(4,699)
Retained earnings (deficit)		(1,722,936)		(1,680,751)
Total shareholders’ equity		367,732		404,528
Noncontrolling interests		348,331		340,213
Total liabilities and equity		4,040,064		4,415,928
IRT
Investments in real estate
Investments in real estate		1,314,115		1,372,015
Accumulated depreciation		(45,059)		(39,638)
Variable Interest Entities
Investments in mortgages and loans, at amortized cost:
Commercial mortgages, mezzanine loans, other loans and preferred equity interests		1,963,873		2,242,416
Allowance for loan losses		0
Total investment in mortgages and loans, net (including $1,272,536 and $1,428,961 held by consolidated VIEs, respectively)		1,963,873		2,242,416
Investments in real estate
Investments in real estate		1,590,511		1,650,789
Accumulated depreciation		(76,253)		(66,036)
Total investments in real estate		1,514,258		1,584,753
Cash and cash equivalents		30,271		39,890
Restricted cash		23,257		23,216
Accrued interest receivable		72,924		77,130
Other assets		18,077		17,581
Intangible assets
Intangible assets		22,088		20,532
Accumulated amortization		(18,638)		(12,997)
Total intangible assets		3,450		7,535
Total assets		3,626,110		3,992,521
Liabilities and Equity
Indebtedness, net		2,848,465		3,330,468
Accrued interest payable		20,683		17,443
Accounts payable and accrued expenses		23,840		25,312
Derivative liabilities		1,950		4,672
Deferred taxes, borrowers’ escrows and other liabilities		9,114		10,022
Total liabilities		2,904,052		3,387,917
Shareholders’ equity:
Accumulated other comprehensive income (loss)		(1,984)		(4,699)
RAIT investment		287,122		190,887
Retained earnings (deficit)		91,106		81,731
Total shareholders’ equity		376,244		267,919
Noncontrolling interests		345,814		336,685
Total liabilities and equity		3,626,110		3,992,521
Variable Interest Entities | RAIT Securitizations
Investments in mortgages and loans, at amortized cost:
Commercial mortgages, mezzanine loans, other loans and preferred equity interests		1,618,072		2,242,416
Total investment in mortgages and loans, net (including $1,272,536 and $1,428,961 held by consolidated VIEs, respectively)		1,618,072		2,242,416
Investments in real estate
Restricted cash		11,891		14,944
Accrued interest receivable		71,481		77,130
Other assets		498		479
Intangible assets
Total assets		1,701,942		2,334,969
Liabilities and Equity
Indebtedness, net		1,387,751		2,090,091
Accrued interest payable		1,367		2,207
Accounts payable and accrued expenses		2		8
Derivative liabilities		787		4,672
Deferred taxes, borrowers’ escrows and other liabilities				176
Total liabilities		1,389,907		2,097,154
Shareholders’ equity:
Accumulated other comprehensive income (loss)		(789)		(4,691)
RAIT investment		151,340		86,822
Retained earnings (deficit)		161,484		155,684
Total shareholders’ equity		312,035		237,815
Total liabilities and equity		1,701,942		2,334,969
Variable Interest Entities | IRT
Investments in real estate
Investments in real estate		1,314,115		1,372,015
Accumulated depreciation		(45,059)		(39,638)
Total investments in real estate		1,269,056		1,332,377
Cash and cash equivalents		28,051		38,301
Restricted cash		6,779		5,413
Other assets		3,985		3,362
Intangible assets
Intangible assets		15,287		15,287
Accumulated amortization		(15,287)		(11,551)
Total intangible assets				3,736
Total assets		1,307,871		1,383,189
Liabilities and Equity
Indebtedness, net		880,287		966,611
Accrued interest payable		701		1,239
Accounts payable and accrued expenses		17,807		19,304
Derivative liabilities		1,163
Deferred taxes, borrowers’ escrows and other liabilities		5,964		6,004
Total liabilities		905,922		993,158
Shareholders’ equity:
Accumulated other comprehensive income (loss)		(1,195)		(8)
RAIT investment		58,194		68,273
Retained earnings (deficit)		(2,600)		(14,499)
Total shareholders’ equity		54,399		53,766
Noncontrolling interests		347,550		336,265
Total liabilities and equity		1,307,871		1,383,189
Variable Interest Entities | RAIT VIE Properties
Investments in real estate
Investments in real estate		276,396		278,774
Accumulated depreciation		(31,194)		(26,398)
Total investments in real estate		245,202		252,376
Cash and cash equivalents		2,218		1,589
Restricted cash		4,582		2,859
Other assets		13,594		13,740
Intangible assets
Intangible assets		6,801		5,245
Accumulated amortization		(3,351)		(1,446)
Total intangible assets		3,450		3,799
Total assets		269,046		274,363
Liabilities and Equity
Indebtedness, net		273,140		273,766
Accrued interest payable		17,953		13,997
Accounts payable and accrued expenses		6,031		6,000
Deferred taxes, borrowers’ escrows and other liabilities		3,150		3,842
Total liabilities		300,274		297,605
Shareholders’ equity:
RAIT investment		38,972		35,792
Retained earnings (deficit)		(68,464)		(59,454)
Total shareholders’ equity		(29,492)		(23,662)
Noncontrolling interests		(1,736)		420
Total liabilities and equity		269,046		$ 274,363
Variable Interest Entities | RAIT Venture VIE
Investments in mortgages and loans, at amortized cost:
Commercial mortgages, mezzanine loans, other loans and preferred equity interests		345,801
Total investment in mortgages and loans, net (including $1,272,536 and $1,428,961 held by consolidated VIEs, respectively)		345,801
Investments in real estate
Cash and cash equivalents		2
Restricted cash		5
Accrued interest receivable		1,443
Intangible assets
Total assets		347,251
Liabilities and Equity
Indebtedness, net		307,287
Accrued interest payable		662
Total liabilities		307,949
Shareholders’ equity:
RAIT investment		38,616
Retained earnings (deficit)		686
Total shareholders’ equity		39,302
Total liabilities and equity		$ 347,251

[1] As of June 30, 2016, includes properties owned by Independence Realty Trust, Inc., or IRT, with a book value of $1,314,115 and accumulated depreciation of $45,059. As of December 31, 2015, includes properties owned by IRT, with a book value of $1,372,015 and accumulated depreciation of $39,638.