Loans Receivable - Principal Balance and Net Book Value of Loans Receivable Based on Internal Risk Ratings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 SecurityLoan	Dec. 31, 2012 SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Book value, net	$ 2,047,223	$ 141,500
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans	31	7
Principal Balance	2,076,411	164,180
Book value, net	2,047,223	141,500
Risk Rating 1-3 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans	29	2
Principal Balance	2,038,863	47,000
Book value, net	2,020,223	47,000
Risk Rating 4-5 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans		2
Principal Balance		92,500
Book value, net		92,500
Risk Rating 6-8 [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans	2	3
Principal Balance	37,548	24,680
Book value, net	$ 27,000	$ 2,000