Fair Value Disclosure Fair Value Disclosure - Other Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	$ 12,142.8	$ 12,313.3
Recourse debt (1)	12,427.3	12,451.7
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Recourse Fixed Rate Debt Fair Value Disclosure	9,612.8	8,622.5
Recourse Floating Rate Debt Fair Value Disclosure	2,814.5	3,829.2
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Recourse Fixed Rate Debt Fair Value Disclosure	9,302.5	8,443.1
Recourse Floating Rate Debt Fair Value Disclosure	$ 2,840.3	$ 3,870.2