Fair Values - Schedule of Details of Carrying Amount, Face Amount, and Approximate Fair Value of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financial assets
Loans receivable, net	$ 40,665
Financial liabilities
Repurchase obligations	1,100,000
Carrying Amount [Member]
Financial assets
Cash and cash equivalents	52,342	15,423
Restricted cash	10,096	14,246
Loans receivable, net	2,047,223	141,500
Financial liabilities
Secured notes		8,497
Repurchase obligations	1,109,353
Convertible notes, net	159,524
Securitized debt obligations	40,181	139,184
Participations sold	90,000
Face Amount [Member]
Financial assets
Cash and cash equivalents	52,342	15,423
Restricted cash	10,096	14,246
Loans receivable, net	2,076,411	164,180
Financial liabilities
Secured notes		8,497
Repurchase obligations	1,109,353
Convertible notes, net	172,500
Securitized debt obligations	40,181	139,184
Participations sold	90,000
Fair Value [Member]
Financial assets
Cash and cash equivalents	52,342	15,423
Restricted cash	10,096	14,246
Loans receivable, net	2,058,699	133,682
Financial liabilities
Secured notes		7,374
Repurchase obligations	1,109,353
Convertible notes, net	181,772
Securitized debt obligations	25,696	89,880
Participations sold	$ 90,304