Loans Receivable, Net - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Loans Receivable, Beginning Balance Principal Balance	$ 16,277,343
Loan fundings Principal Balance	1,240,642
Loans repayments Principal Balance	(953,069)
Unrealized (loss) gain on foreign currency translation Principal Balance	(130,285)
Loans Receivable, Ending Balance Principal Balance	16,434,631
Loans Receivable, Beginning Balance Deferred Fees/ Other Items	(112,542)
Unrealized (loss) gain on foreign currency translation Deferred Fees/ Other Items	1,232
Amortization of fees and other items Deferred Fees/ Other Items	28,051
Loans Receivable, Ending Balance Deferred Fees/ Other Items	(95,228)
Loans Receivable, Beginning Balance Net Book Value	16,164,801
Loan fundings Net Book Value	1,240,642
Loans repayments Principal Balance	(953,069)
Unrealized (loss) gain on foreign currency translation Net Book Value	(129,053)
Deferred fees and other items	(11,969)
Amortization of fees and other items Net Book Value	28,051
Loans Receivable, Ending Balance Net Book Value	16,339,403
CECL reserve	(178,050)	$ (112,694)	$ 0
Net book value of restructured loan	$ 16,161,353		$ 16,164,801