Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio (Detail) $ in Thousands	6 Months Ended				12 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2025 USD ($) loan	Jun. 30, 2025 USD ($) security_loan	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($) loan	Dec. 31, 2024 USD ($) security_loan	Dec. 31, 2024 USD ($)	Dec. 31, 2023	Jun. 30, 2024 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans		144	144			130	130
Principal balance	$ 19,874,340	$ 19,874,340	$ 19,874,340	$ 19,874,340	$ 19,203,126	$ 19,203,126	$ 19,203,126	$ 19,203,126
Net book value	18,965,254	18,965,254	18,965,254	18,965,254	18,313,582	18,313,582	18,313,582	18,313,582
Unfunded loan commitments	$ 11,713	$ 11,713	$ 11,713	$ 11,713	$ 10,412	$ 10,412	$ 10,412	$ 10,412		$ 9,900
Weighted-average cash coupon (percentage)	3.30%	3.30%	3.30%	3.30%	3.46%	3.46%	3.46%	3.46%
Weighted-average all-in yield (percentage)				3.57%				3.78%
Weighted-average maximum maturity (years)	2 years 4 months 24 days				2 years 1 month 6 days
Debt instrument, variable interest rate, type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR)				Secured Overnight Financing Rate (SOFR)				Secured Overnight Financing Rate (SOFR)
Percentage of loans by principal balance, floating rate	98.00%	98.00%	98.00%	98.00%
Percentage of loans by principal balance, fixed rate	2.00%	2.00%	2.00%	2.00%
Percent of loans subject to prepayment restrictions	26.00%	26.00%	26.00%	26.00%	10.00%	10.00%	10.00%	10.00%
Percent of loans not subject to prepayment restrictions	74.00%	74.00%	74.00%	74.00%	90.00%	90.00%	90.00%	90.00%
Unfunded Loan Commitment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan		58
Unfunded loan commitments	$ 1,412,084	$ 1,412,084	$ 1,412,084	$ 1,412,084	$ 1,263,068	$ 1,263,068	$ 1,263,068	$ 1,263,068