Investments in Affiliated Companies (Details) - USD ($) $ in Millions		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Investments in Affiliated Companies		$ 732.3	$ 663.3	$ 627.0
Rolls Royce Partners Finance [Member]
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	[1]	50.00%
RailPulse
Schedule of Equity Method Investments [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		10.00%
Portfolio Management [Member]
Schedule of Equity Method Investments [Line Items]
Investments in Affiliated Companies		$ 732.3	663.1	626.8
Portfolio Management [Member] | Rolls Royce Partners Finance [Member]
Schedule of Equity Method Investments [Line Items]
Investments in Affiliated Companies			663.1
Rail North America [Member]
Schedule of Equity Method Investments [Line Items]
Investments in Affiliated Companies				$ 0.2
Rail North America [Member] | RailPulse
Schedule of Equity Method Investments [Line Items]
Investments in Affiliated Companies		$ 0.0	$ 0.2

[1] (1) Combined investment balances of a group of 50.0% owned domestic and foreign joint ventures with Rolls-Royce