Secured Debt, Net - Schedule of Secured Credit Facilities (Detail) - Secured credit facilities - Line of Credit $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) lender	Dec. 31, 2021 USD ($)
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	14
Borrowings | $	$ 13,117,249	$ 12,299,580
Loan Count | lender	185
Collateral | $	$ 18,710,706	$ 17,042,381
Recourse Limitation Wtd. Avg. (percentage)	35.00%
Others
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	4
Borrowings | $	$ 965,379
Loan Count | lender	7
Collateral | $	$ 1,247,765
Recourse Limitation Wtd. Avg. (percentage)	25.00%
Recourse Limitation Range (percentage)	25.00%
Minimum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	25.00%
Maximum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	100.00%
USD
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	14
Borrowings | $	$ 7,961,788
Loan Count | lender	153
Collateral | $	$ 11,890,070
Recourse Limitation Wtd. Avg. (percentage)	35.00%
USD | Minimum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	25.00%
USD | Maximum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	100.00%
EUR
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	6
Borrowings | $	$ 2,288,852
Loan Count | lender	10
Collateral | $	$ 3,060,991
Recourse Limitation Wtd. Avg. (percentage)	46.00%
EUR | Minimum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	25.00%
EUR | Maximum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	100.00%
GBP
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	6
Borrowings | $	$ 1,901,230
Loan Count | lender	17
Collateral | $	$ 2,511,880
Recourse Limitation Wtd. Avg. (percentage)	26.00%
GBP | Minimum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	25.00%
GBP | Maximum
Schedule Of Secured Credit Facilities [Line Items]
Recourse Limitation Range (percentage)	50.00%