Notes and Other Debt, Net - Asset-Backed Bridge Loan Facility (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Feb. 03, 2025	Dec. 31, 2024	Feb. 23, 2024
Debt Instrument [Line Items]
Total principal amount	$ 9,261.5		$ 9,261.5			$ 5,861.5
Loss on extinguishment of debt	0.0	$ 0.0	(40.5)	$ 0.0
ABS Credit Agreement
Debt Instrument [Line Items]
Loss on extinguishment of debt			(3.2)
ABS Loan Facility
Debt Instrument [Line Items]
Total principal amount	0.0		0.0		$ 589.0	275.0
5.877% Series 2025-1, Class A-2 term notes
Debt Instrument [Line Items]
Total principal amount	$ 426.0		$ 426.0		426.0	0.0
Issuance senior notes, stated percentage	5.877%		5.877%
Six Point Thirty Six Nine Percentage ABS Notes (Class B) Due April One Two Thounsad Thirty
Debt Instrument [Line Items]
Total principal amount	$ 65.0		$ 65.0		65.0	0.0
Issuance senior notes, stated percentage	6.369%		6.369%
Nine Point Zero One Eight Percentage ABS Notes (Class C) Due April One Two Thounsad Thirty
Debt Instrument [Line Items]
Total principal amount	$ 98.0		$ 98.0		98.0	0.0
Issuance senior notes, stated percentage	9.018%		9.018%
Senior secured notes - 10.50%, due February 15, 2028 (discount is based on imputed interest rate of 10.99%)
Debt Instrument [Line Items]
Total principal amount	$ 2,275.0		$ 2,275.0			2,900.0
Issuance senior notes, stated percentage	10.50%		10.50%
Aggregate principal amount					$ 125.0
2028 Secured Notes
Debt Instrument [Line Items]
Issuance senior notes, stated percentage					103.00%
Loss on extinguishment of debt			$ (5.3)
Debt issuance costs, net			4.8
Interest expense			$ 3.7
Revolving Credit Facility | Line of Credit | ABS Credit Agreement
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity							$ 350.0
Total principal amount						$ 275.0