Equity Investments - Summary Financial Information of Cash Flow for Unconsolidated Subsidiaries (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents at end of year			$ 112,512
WRT One South State Lender LP [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 7,639	$ 7,865	879
Net cash provided by investing activities	(3,998)
Net cash used in financing activities	(3,641)	(7,865)	(5,952)
Non cash investing and financing activity
Distribution to partners			(4,166)
Contribution from partners		20
RE CDO Management LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	97	104	(7)
Net cash provided by investing activities			8,940
Net cash used in financing activities	(84)	(141)	(8,993)
Cash and cash equivalents at end of year	$ 39	$ 26	$ 63