Secured Debt, Net - Schedule of Secured Credit Facilities (Detail) - Secured credit facilities - Line of Credit $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) lender	Dec. 31, 2021 USD ($)
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	15
Borrowings | $	$ 13,213,212	$ 12,299,580
Loan Count | lender	188
Collateral | $	$ 18,962,300	$ 17,042,381
Recourse Limitation Wtd. Avg. (percentage)	34.00%
Others
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	4
Borrowings | $	$ 1,532,713
Loan Count | lender	8
Collateral | $	$ 1,944,598
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 | $	$ 7,627,832
Loan Count | lender	149
Collateral | $	$ 11,656,788
Recourse Limitation Wtd. Avg. (percentage)	36.00%
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%
GBP
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	7
Borrowings | $	$ 2,074,791
Loan Count | lender	21
Collateral | $	$ 2,729,052
Recourse Limitation Wtd. Avg. (percentage)	27.00%
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%
EUR
Schedule Of Secured Credit Facilities [Line Items]
Lenders | lender	7
Borrowings | $	$ 1,977,876
Loan Count | lender	11
Collateral | $	$ 2,631,862
Recourse Limitation Wtd. Avg. (percentage)	42.00%
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%