Equity Investments - Summary Financial Information of Cash Flow for Unconsolidated Subsidiaries (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 30,268	$ 46,435	$ 39,687
Net cash provided by (used in) investment	(182,278)	(109,447)	(105,350)
Net cash provided by (used in) financing activities	166,840	119,742	61,358
Cash and cash equivalents at end of year	112,512	97,682	40,952	45,257
RE CDO Management LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(7)	292	119
Net cash provided by (used in) investment	8,940	(1,093)	(2,525)
Net cash provided by (used in) financing activities	(8,993)	830	2,500
Cash and cash equivalents at end of year	63	123	94
WRT-One South State Lender LP [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	879	4,967
Net cash provided by (used in) investment		(21,369)	(20,150)
Net cash provided by (used in) financing activities	(5,952)	21,475	20,150
Cash and cash equivalents at end of year		5,073
Non cash investing and financing activity
Distribution to partners	$ (4,166)