Investments in Loans and Financing Receivables - Schedule of Loans Receivables (Details) $ in Thousands, € in Millions, £ in Millions	1 Months Ended			4 Months Ended	9 Months Ended
	Jul. 31, 2025 GBP (£)	Jun. 30, 2025 GBP (£)	Feb. 28, 2025 USD ($) extension_option	Sep. 30, 2025 USD ($) note	Sep. 30, 2025 USD ($) note	Sep. 30, 2024 USD ($)	Sep. 30, 2025 GBP (£) note	Jul. 31, 2025 EUR (€)	Jul. 31, 2025 GBP (£)	Jun. 30, 2025 USD ($) extension_option	Dec. 31, 2024 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance				$ (113,200)	$ (113,200)					$ (101,800)	$ (111,500)
Investment in loans					$ 807,433	$ 377,490
Senior Secured Notes Receivable
Financing Receivable, Allowance for Credit Loss [Line Items]
Number of interest-only notes bearing interest, held | note				3	3		3
Loans Receivable
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal				$ 1,715,000	$ 1,715,000						848,200
Amortized Cost				1,705,600	1,705,600						840,800
Allowance				(25,900)	(25,900)					$ (14,800)	(12,300)
Carrying Amount				1,679,700	1,679,700						828,500
Accrued interest				$ 39,300	$ 39,300						$ 13,800
Loans Receivable | Senior Secured Notes Receivable
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				8.00%	8.00%		8.00%				8.125%
Basis spread on variable rate (as a percent)				5.75%	5.75%		5.75%				5.75%
Principal				$ 1,249,200	$ 1,249,200						$ 803,700
Amortized Cost				1,239,500	1,239,500						797,200
Allowance				(22,600)	(22,600)						(11,400)
Carrying Amount				$ 1,216,900	$ 1,216,900						$ 785,800
Payments to acquire notes receivable | £	£ 197.0
Loans Receivable | EUR-Denominated Senior Secured Notes Due July 2031
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				8.00%	8.00%		8.00%
Principal				$ 117,400	$ 117,400			€ 100.0
Loans Receivable | GBP-Denominated Senior Secured Notes
Financing Receivable, Allowance for Credit Loss [Line Items]
Basis spread on variable rate (as a percent)				5.36%	5.36%		5.36%
Principal				$ 268,800	$ 268,800				£ 200.0
Credit adjustment spread (as a percent)				0.11%	0.11%		0.11%
Loans Receivable | GBP-Denominated Senior Secured Notes | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Basis spread on variable rate (as a percent)				4.50%	4.50%		4.50%
Loans Receivable | GBP-Denominated Senior Secured Notes | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Basis spread on variable rate (as a percent)				5.25%	5.25%		5.25%
Loans Receivable | Mortgage Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)											8.37%
Principal				$ 251,100	$ 251,100						$ 33,500
Amortized Cost				251,200	251,200						33,500
Allowance				(100)	(100)						0
Carrying Amount				$ 251,100	$ 251,100						$ 33,500
Loans Receivable | Mortgage Loans | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				7.50%	7.50%		7.50%
Loans Receivable | Mortgage Loans | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				8.37%	8.37%		8.37%
Loans Receivable | Mortgage Loan Secured By an Office Property
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)										7.50%
Principal amount, acquired		£ 121.5		$ 163,300
Funding commitments | £							£ 20.5
Loans Receivable | Mortgage Loan Secured By a Logistics Property
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)										7.50%
Principal amount, acquired		£ 40.3		54,300
Funding commitments | £							£ 8.4
Number of extension options | extension_option										1
Extension option term		12 months
Loans Receivable | Unsecured and Other Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal				214,700	$ 214,700
Amortized Cost				214,900	214,900
Allowance				(3,200)	(3,200)
Carrying Amount				$ 211,700	$ 211,700
Principal amount, acquired			$ 200,000
Number of extension options | extension_option			2
Extension option term			12 months
Cash rate (as a percent)			10.25%
Payment-in-kind rate (as a percent)			10.75%
Investment in loans			$ 199,800
Origination costs			$ 1,100
Loans Receivable | Unsecured and Other Loans | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				10.25%	10.25%		10.25%
Loans Receivable | Unsecured and Other Loans | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)				11.00%	11.00%		11.00%
Loans Receivable | Unsecured Loan
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest rate (as a percent)											11.00%
Principal											$ 11,000
Amortized Cost											10,100
Allowance											(900)
Carrying Amount											$ 9,200