Loans Receivable - Activity Relating to Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred origination fees and expenses		$ (21,751)	$ (4,219)
Amortization of deferred fees and expenses		(7,702)	(434)
Unrealized gain on foreign currency translation	1,894	1,930
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
December 31, 2013		2,047,223
Loan fundings		1,740,977
Loan repayments and sales		(265,809)
Deferred origination fees and expenses		(21,751)
Amortization of deferred fees and expenses		7,702
Unrealized gain on foreign currency translation		6,837
Realized loan losses
Reclassification to other assets		(27,000)
June 30, 2014	3,488,179	3,488,179
Deferred Fees and Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
December 31, 2013		(29,188)
Deferred origination fees and expenses		(21,751)
Amortization of deferred fees and expenses		7,702
Unrealized gain on foreign currency translation		6,837
Realized loan losses		10,547
June 30, 2014	(25,853)	(25,853)
Principal Balance [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
December 31, 2013		2,076,411
Loan fundings		1,740,977
Loan repayments and sales		(265,809)
Realized loan losses		(10,547)
Reclassification to other assets		(27,000)
June 30, 2014	$ 3,514,032	$ 3,514,032