Equity Investments - Summary Financial Information of Balance Sheet for Unconsolidated Subsidiaries (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Aug. 01, 2014	Jul. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Balance Sheets
Total assets			$ 1,097,041	$ 1,132,324
Total liabilities				622,661
ASSETS
Loan receivable	24,005			101,100	211,250
Other assets, net				3,314
TOTAL ASSETS			1,097,041	1,132,324
Liabilities and Equity
Accounts payable and accrued expenses				26,266
TOTAL LIABILITIES				622,661
Equity		(476,454)	514,214	509,663	469,264	408,836
Total liabilities and equity				1,132,324
WRT One South State Lender LP [Member]
Balance Sheets
Total assets	49,460			47,201
Total liabilities	2			23
ASSETS
Loan receivable	44,014			42,173
Other assets, net	5,446			5,028
TOTAL ASSETS	49,460			47,201
Liabilities and Equity
Accounts payable and accrued expenses	2			23
Other liabilities	0			0
TOTAL LIABILITIES	2			23
Equity	49,458			47,178
Total liabilities and equity	49,460			47,201
RE CDO Management LLC [Member]
Balance Sheets
Total assets	1,871			1,998
Total liabilities	12			16
ASSETS
Loan receivable	1,002			1,033
Other assets, net	869			965
TOTAL ASSETS	1,871			1,998
Liabilities and Equity
Accounts payable and accrued expenses	12			16
TOTAL LIABILITIES	12			16
Equity	1,859			1,982
Total liabilities and equity	1,871			1,998
Unconsolidated Subsidiaries [Member]
Balance Sheets
Investment in real estate	1,251,615			1,291,651
Total assets	1,453,983			1,504,548
Total debt	913,406			896,094
Total liabilities	179,224			270,109
Non controlling interests	88,363			43,660
ASSETS
TOTAL ASSETS	1,453,983			1,504,548
Liabilities and Equity
TOTAL LIABILITIES	$ 179,224			$ 270,109