Loans Receivable, Net - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Beginning Balance	$ 16,164,801
Unrealized (loss) gain on foreign currency translation	(69,510)	$ 5,414
Amortization of fees and other items	14,399	$ 13,356
Loans Receivable, Ending Balance	16,363,608
CECL reserve	112,694		$ 112,694
Net book value of restructured loan	16,250,914		$ 16,164,801
Net Book Value [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Beginning Balance	16,164,801
Loan fundings	971,322
Loans repayments	(567,352)
Unrealized (loss) gain on foreign currency translation	(210,818)
Deferred fees and other items	(8,610)
Amortization of fees and other items	14,265
Loans Receivable, Ending Balance	16,363,608
CECL reserve	(112,694)
Net book value of restructured loan	16,250,914
Deferred Fees/Other Items [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Beginning Balance	(112,542)
Loan fundings	0
Loans repayments	0
Unrealized (loss) gain on foreign currency translation	1,728
Deferred fees and other items	(8,610)
Amortization of fees and other items	14,265
Loans Receivable, Ending Balance	(105,159)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable, Beginning Balance	16,277,343
Loan fundings	971,322
Loans repayments	(567,352)
Unrealized (loss) gain on foreign currency translation	(212,546)
Deferred fees and other items	0
Amortization of fees and other items	0
Loans Receivable, Ending Balance	16,468,767
Loans Receivable, Ending Balance	16,363,608
CECL reserve	(112,694)
Net book value of restructured loan	$ 16,250,914