Equity Investments - Trust's Carrying Amounts in its Equity Investments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	$ 190,737	$ 149,085
Sealy [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	7,507	7,635
Vintage Housing Holdings LLC [Member] | Gancar Trust [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	75.00%
Equity investments	34,386	34,153
WRT-Elad One South State Lender LP [Member] | Elad Canada Ltd [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	23,927	23,661
WRT One South State Lender LP [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	23,927	23,661
WRT One South State Lender LP [Member] | Elad Canada Ltd [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments
WRT-Stamford LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	9,208	9,064
WRT-Stamford LLC [Member] | Mack-Cali [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	20.00%
Equity investments	9,208	9,064
10 Metrotech Loan LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	11	11
10 Metrotech Loan LLC [Member] | Atrium/Northstar [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	33.30%
Equity investments	11	11
RE CDO Management LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	996	992
RE CDO Management LLC [Member] | Atrium Holding [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	996	992
Mentor Retail LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	585	635
Mentor Retail LLC [Member] | Freed [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	49.90%
Equity investments	585	635
Concord Debt Holdings LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments
Concord Debt Holdings LLC [Member] | Inland/Lexington [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	33.30%
Equity investments
Concord Debt Holdings LLC [Member] | Inland [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	33.30%
Equity investments	790	966
CDH CDO LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments
CDH CDO LLC [Member] | Inland/Lexington [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	24.80%
Equity investments
CDH CDO LLC [Member] | Inland [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	24.80%
Equity investments	4,615	4,215
Northwest Atlanta Partners LP [Member] | Sealy [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	60.00%
Equity investments	7,507	7,635
Brooks Building LLC [Member] | Marc Realty [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	6,546	6,551
High Point Plaza LLC [Member] | Marc Realty [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments
1701 Woodfield LLC [Member] | Marc Realty [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments		150
Enterprise Center LLC [Member] | Marc Realty [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments		50
Atrium Mall LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	3,776	3,845
Atrium Mall LLC [Member] | Marc Realty [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	3,776	3,845
WRT - ROIC Lakeside Eagle LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	4
WRT - ROIC Lakeside Eagle LLC [Member] | ROIC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	4
701 7th WRT Investors LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	96,147	55,259
701 7th WRT Investors LLC [Member] | New Valley/Witkoff [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	70.50%
Equity investments	96,147	55,259
WRT-Fenway Wateridge LLC [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	1,989	1,898
WRT-Fenway Wateridge LLC [Member] | Fenway [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	50.00%
Equity investments	1,989	1,898
Edens Plaza Associates LLC [Member] | Freed [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Nominal % Ownership	1.00%
Equity investments	$ 250