Equity Investments - Trust's Carrying Amounts in its Equity Investments (Detail) (USD $)	Dec. 31, 2013	Oct. 07, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Sealy [Member]	Dec. 31, 2012 Sealy [Member]	Dec. 31, 2011 Sealy [Member]	Dec. 31, 2013 Vintage Housing Holdings, LLC [Member]	Dec. 31, 2012 Vintage Housing Holdings, LLC [Member]	Dec. 31, 2011 Vintage Housing Holdings, LLC [Member]	Dec. 31, 2013 Vintage Housing Holdings, LLC [Member] Gancar Trust [Member]	Dec. 31, 2012 Vintage Housing Holdings, LLC [Member] Gancar Trust [Member]	Dec. 31, 2013 WRT-Elad One South State Equity LP [Member]	Dec. 31, 2012 WRT-Elad One South State Equity LP [Member]	Dec. 31, 2011 WRT-Elad One South State Equity LP [Member]	Dec. 31, 2013 WRT-Elad One South State Equity LP [Member] Elad Canada Ltd [Member]	Dec. 31, 2012 WRT-Elad One South State Equity LP [Member] Elad Canada Ltd [Member]	Dec. 31, 2013 WRT-One South State Lender LP [Member]	Dec. 31, 2012 WRT-One South State Lender LP [Member]	Dec. 31, 2011 WRT-One South State Lender LP [Member]	Dec. 31, 2013 WRT-One South State Lender LP [Member] Elad Canada Ltd [Member]	Dec. 31, 2012 WRT-One South State Lender LP [Member] Elad Canada Ltd [Member]	Dec. 31, 2013 WRT-Stamford LLC [Member]	Dec. 31, 2012 WRT-Stamford LLC [Member]	Dec. 31, 2011 WRT-Stamford LLC [Member]	Dec. 31, 2013 WRT-Stamford LLC [Member] Mack-Cali [Member]	Dec. 31, 2012 WRT-Stamford LLC [Member] Mack-Cali [Member]	Dec. 31, 2013 10 Metrotech Loan LLC [Member]	Dec. 31, 2012 10 Metrotech Loan LLC [Member]	Aug. 31, 2012 10 Metrotech Loan LLC [Member]	Dec. 31, 2011 10 Metrotech Loan LLC [Member]	Dec. 31, 2013 10 Metrotech Loan LLC [Member] Atrium/Northstar [Member]	Dec. 31, 2012 10 Metrotech Loan LLC [Member] Atrium/Northstar [Member]	Dec. 31, 2013 RE CDO Management LLC [Member]	Feb. 20, 2013 RE CDO Management LLC [Member]	Dec. 31, 2012 RE CDO Management LLC [Member]	Dec. 31, 2011 RE CDO Management LLC [Member]	Dec. 31, 2013 RE CDO Management LLC [Member] Atrium Holding [Member]	Dec. 31, 2012 RE CDO Management LLC [Member] Atrium Holding [Member]	Dec. 31, 2013 Mentor Retail LLC [Member]	Dec. 31, 2012 Mentor Retail LLC [Member]	Dec. 31, 2011 Mentor Retail LLC [Member]	Dec. 31, 2013 Mentor Retail LLC [Member] Freed [Member]	Dec. 31, 2012 Mentor Retail LLC [Member] Freed [Member]	Dec. 31, 2013 Concord Debt Holdings LLC [Member]	Dec. 31, 2012 Concord Debt Holdings LLC [Member]	Dec. 31, 2011 Concord Debt Holdings LLC [Member]	Dec. 31, 2013 Concord Debt Holdings LLC [Member] Inland/Lexington [Member]	Dec. 31, 2012 Concord Debt Holdings LLC [Member] Inland/Lexington [Member]	Dec. 31, 2013 Concord Debt Holdings LLC [Member] Inland [Member]	Dec. 31, 2012 Concord Debt Holdings LLC [Member] Inland [Member]	Dec. 31, 2013 CDH CDO LLC [Member]	Dec. 31, 2012 CDH CDO LLC [Member]	Dec. 31, 2011 CDH CDO LLC [Member]	Dec. 31, 2013 CDH CDO LLC [Member] Inland/Lexington [Member]	Dec. 31, 2012 CDH CDO LLC [Member] Inland/Lexington [Member]	Dec. 31, 2013 CDH CDO LLC [Member] Inland [Member]	Dec. 31, 2012 CDH CDO LLC [Member] Inland [Member]	Dec. 31, 2013 Northwest Atlanta Partners LP [Member] Sealy [Member]	Dec. 31, 2012 Northwest Atlanta Partners LP [Member] Sealy [Member]	Dec. 31, 2013 Sealy Newmarket General Partnership [Member] Sealy [Member]	Dec. 31, 2012 Sealy Newmarket General Partnership [Member] Sealy [Member]	Dec. 31, 2013 Airpark Nashville GP [Member] Sealy [Member]	Dec. 31, 2012 Airpark Nashville GP [Member] Sealy [Member]	Dec. 31, 2013 Brooks Building LLC [Member] Marc Realty [Member]	Dec. 31, 2012 Brooks Building LLC [Member] Marc Realty [Member]	Dec. 31, 2013 High Point Plaza LLC [Member] Marc Realty [Member]	Dec. 31, 2012 High Point Plaza LLC [Member] Marc Realty [Member]	Dec. 31, 2013 1701 Woodfield LLC [Member] Marc Realty [Member]	Dec. 31, 2012 1701 Woodfield LLC [Member] Marc Realty [Member]	Dec. 31, 2013 Enterprise Center LLC [Member] Marc Realty [Member]	Dec. 31, 2012 Enterprise Center LLC [Member] Marc Realty [Member]	Dec. 31, 2013 Atrium Mall LLC [Member]	Dec. 31, 2012 Atrium Mall LLC [Member]	Dec. 31, 2013 Atrium Mall LLC [Member] Marc Realty [Member]	Dec. 31, 2012 Atrium Mall LLC [Member] Marc Realty [Member]	Dec. 31, 2013 WRT - ROIC Lakeside Eagle LLC [Member]	Dec. 31, 2012 WRT - ROIC Lakeside Eagle LLC [Member]	Dec. 31, 2011 WRT - ROIC Lakeside Eagle LLC [Member]	Dec. 31, 2013 WRT - ROIC Lakeside Eagle LLC [Member] ROIC [Member]	Dec. 31, 2012 WRT - ROIC Lakeside Eagle LLC [Member] ROIC [Member]	Dec. 31, 2013 Socal Office Portfolio Loan LLC [Member]	Dec. 31, 2012 Socal Office Portfolio Loan LLC [Member]	Dec. 31, 2011 Socal Office Portfolio Loan LLC [Member]	Dec. 31, 2013 Socal Office Portfolio Loan LLC [Member] New Valley/Starwood [Member]	Dec. 31, 2012 Socal Office Portfolio Loan LLC [Member] New Valley/Starwood [Member]	Dec. 31, 2013 701 7th WRT Investors LLC [Member]	Dec. 31, 2012 701 7th WRT Investors LLC [Member]	Dec. 31, 2011 701 7th WRT Investors LLC [Member]	Dec. 31, 2013 701 7th WRT Investors LLC [Member] New Valley/Witkoff [Member]	Dec. 31, 2012 701 7th WRT Investors LLC [Member] New Valley/Witkoff [Member]	Dec. 31, 2013 WRT-Fenway Wateridge LLC [Member]	Dec. 31, 2012 WRT-Fenway Wateridge LLC [Member]	Dec. 31, 2011 WRT-Fenway Wateridge LLC [Member]	Dec. 31, 2013 WRT-Fenway Wateridge LLC [Member] Fenway [Member]	Dec. 31, 2012 WRT-Fenway Wateridge LLC [Member] Fenway [Member]
Schedule Of Results Related To Equity Accounted Investees [Line Items]
Equity investments	$ 149,085,000	$ 0	$ 134,859,000	$ 162,142,000	$ 7,635,000	$ 8,104,000	$ 11,348,000	$ 34,153,000	$ 30,534,000	$ 29,887,000	$ 34,153,000	$ 30,534,000		$ 460,000			$ 460,000	$ 23,661,000	$ 24,644,000	$ 10,150,000	$ 23,661,000	$ 24,644,000	$ 9,064,000	$ 8,501,000		$ 9,064,000	$ 8,501,000	$ 11,000	$ 10,845,000			$ 11,000	$ 10,845,000	$ 992,000		$ 1,779,000	$ 1,296,000	$ 992,000	$ 1,779,000	$ 635,000	$ 551,000		$ 635,000	$ 551,000						$ 966,000	$ 3,974,000						$ 4,215,000	$ 322,000	$ 7,635,000	$ 8,104,000					$ 6,551,000	$ 7,983,000		$ 2,241,000	$ 150,000	$ 1,977,000	$ 50,000	$ 2,679,000	$ 3,845,000		$ 3,845,000				$ 7,000				$ 8,000	$ 72,626,000		$ 8,000	$ 55,259,000	$ 28,735,000		$ 55,259,000	$ 28,735,000	$ 1,898,000	$ 1,522,000		$ 1,898,000	$ 1,522,000
Nominal % Ownership											75.00%					50.00%					50.00%					20.00%				33.33%		33.30%			50.00%			50.00%					49.90%					33.30%		33.30%					24.80%		24.80%		60.00%		68.00%		50.00%		50.00%		50.00%		50.00%		50.00%				50.00%					50.00%					73.00%					70.50%					50.00%