Loans Receivable, Net - Schedule Of Loan Receivable Portfolio Based On Floor Rate (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	$ 20,522,560	$ 16,652,824
Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	5,920,295
USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	14,602,265
Fixed rate
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	78,511
Fixed rate | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	78,511
Fixed rate | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	0
0.00% or no floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	8,178,545
0.00% or no floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	4,912,695
0.00% or no floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	3,265,850
0.01% to 0.24% floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	4,022,159
0.01% to 0.24% floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	112,026
0.01% to 0.24% floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	3,910,133
0.25% to 0.99% floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	1,635,301
0.25% to 0.99% floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	271,616
0.25% to 0.99% floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	1,363,685
1.00% or more floor
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	6,608,044
1.00% or more floor | Non-USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	545,447
1.00% or more floor | USD [Member]
Disclosure Details Of Loan Receivable Portfolio Based On Floor Rate [Line Items]
Principal balance	$ 6,062,597