Loans Receivable - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	$ 4,428,500
Loan originations, acquisitions, and fundings	7,203,145	$ 3,067,263	$ 2,327,914
Amortization of fees and other items	(36,052)	(19,785)	(5,965)
Reclassification to other assets		(27,000)
Ending Balance	9,077,007	4,428,500
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	4,428,500	2,047,223
Loan originations, acquisitions, and fundings	7,203,145	3,067,263
Loan repayments	(2,407,920)	(591,246)
Unrealized (loss) gain on foreign currency translation	(149,269)	(52,076)
Deferred fees and other items	33,501	35,449
Amortization of fees and other items	36,052	19,785
Reclassification to other assets		(27,000)
Ending Balance	9,077,007	4,428,500	2,047,223
Deferred Fees/Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	(34,397)	(30,004)
Unrealized (loss) gain on foreign currency translation	492	725
Deferred fees and other items	(33,501)	(35,449)
Amortization of fees and other items	36,052	19,785
Charge-offs		10,546
Ending Balance	(31,354)	(34,397)	(30,004)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	4,462,897	2,077,227
Beginning Balance	4,428,500
Loan originations, acquisitions, and fundings	7,203,145	3,067,263
Loan repayments	(2,407,920)	(591,246)
Unrealized (loss) gain on foreign currency translation	(149,761)	(52,801)
Charge-offs		10,546
Reclassification to other assets		(27,000)
Ending Balance	9,108,361	4,462,897	$ 2,077,227
Ending Balance	$ 9,077,007	$ 4,428,500