Borrowings - Narrative (Details) - USD ($)	Dec. 31, 2025	Feb. 23, 2024	Feb. 15, 2024	Nov. 21, 2023	Sep. 29, 2023	Jun. 28, 2023	Feb. 24, 2023	May 25, 2022	Sep. 30, 2025	Jul. 15, 2025	Jul. 23, 2024	Nov. 14, 2023	Mar. 25, 2022
Line of Credit Facility [Line Items]
Derivative interest rate (as a percent)										6.19%	6.50%	8.40%
Floating interest rate (as a percent)										2.4926%	2.5954%	4.0405%
Notional amount										$ 400,000,000	$ 400,000,000	$ 350,000,000
Line of Credit
Line of Credit Facility [Line Items]
Aggregate amount	$ 2,735,000,000								$ 2,735,000,000
Unsecured Notes
Line of Credit Facility [Line Items]
Debt instrument, face amount	1,150,000,000								1,150,000,000
ING Credit Agreement | Line of Credit
Line of Credit Facility [Line Items]
Aggregate amount	$ 1,235,000,000								1,235,000,000
Unused capacity, commitment fee (as a percent)	0.375%
Accordion feature, increase limit													$ 1,750,000,000
Accordion feature, increase limit, percentage of shareholders' equity (as a percent)													150.00%
ING Credit Agreement | Line of Credit | Secured Overnight Financing Rate (SOFR) | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)	1.875%
ING Credit Agreement | Line of Credit | Base Rate | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)	0.875%
ING Credit Agreement | Line of Credit | Alternative Base Rate | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)	0.10%
ING Credit Agreement | Line of Credit | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)						0.50%		0.50%
ING Credit Agreement | Line of Credit | Overnight Bank Funding Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)						0.50%		0.50%
ING Credit Agreement | Letter of Credit
Line of Credit Facility [Line Items]
Aggregate amount	$ 25,000,000
IING Credit Agreement | Secured Overnight Financing Rate (SOFR)
Line of Credit Facility [Line Items]
Interest rate (as a percent)	1.75%
IING Credit Agreement | Base Rate
Line of Credit Facility [Line Items]
Interest rate (as a percent)	0.75%
IING Credit Agreement | Line of Credit | Secured Overnight Financing Rate (SOFR) | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)	0.10%
JPM SPV Facility | Line of Credit
Line of Credit Facility [Line Items]
Aggregate amount	$ 700,000,000.0						$ 700,000,000		700,000,000.0
Debt instrument, basis spread, variable rate (as a percent)							1.50%
Accordion feature, increase limit							$ 1,000,000,000
Tenor period (in months)							3 months
Other Borrowings | Line of Credit
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)		1.85%					1.90%
SMBC SPV Facility | Line of Credit | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)					50.00%
CIBC Loan and Servicing Agreement | Line of Credit | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)				0.50%
DBNY SPV Facility | Line of Credit
Line of Credit Facility [Line Items]
Aggregate amount	400,000,000.0		$ 400,000,000						400,000,000.0
Cost of funds rate, floor (as a percent)			0.25%
Borrowing capacity, increase limit			$ 1,000,000,000
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario One
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)			1.60%
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)			2.25%
DBNY SPV Facility | Line of Credit | Cost of Funds Rate | Interest Rate Scenario Three
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)			2.00%
MS SPV Facility | Line of Credit
Line of Credit Facility [Line Items]
Aggregate amount	$ 400,000,000.0	$ 400,000,000							$ 400,000,000.0
Debt instrument, basis spread, variable rate (as a percent)		1.60%
Accordion feature, increase limit		$ 600,000,000
MS SPV Facility | Line of Credit | Interest Rate Scenario One
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)		1.80%
MS SPV Facility | Line of Credit | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)		0.50%
MS SPV Facility | Line of Credit | Interest Rate Scenario Three
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate (as a percent)		2.00%
Notes due 2028 | Unsecured Notes
Line of Credit Facility [Line Items]
Debt instrument, face amount												$ 350,000,000
Debt interest rate (as a percent)												8.40%
Notes Due 2029 | Unsecured Notes
Line of Credit Facility [Line Items]
Debt instrument, face amount											$ 400,000,000
Debt interest rate (as a percent)											6.50%
Notes Due 2030 | Unsecured Notes
Line of Credit Facility [Line Items]
Debt instrument, face amount										$ 400,000,000
Debt interest rate (as a percent)										6.19%	6.19%