Railcar Leasing and Services Group - Other Operating Lease Obligations & Future Revenues (Details) $ in Millions	Mar. 31, 2024 USD ($)
Future operating lease obligations
Remaining nine months of 2024	$ 15.7
2025	18.9
2026	17.2
2027	16.0
2028	12.5
Thereafter	58.3
Lessee, Operating Lease, Liability, to be Paid, Total	138.6
Railcars on Lease [Member]
Future operating lease obligations
Remaining nine months of 2024	6.6
2025	8.2
2026	7.7
2027	7.2
2028	5.1
Thereafter	6.8
Lessee, Operating Lease, Liability, to be Paid, Total	41.6
Leasing & Services
Future contractual minimum rental revenues
Remaining nine months of 2024	530.2	[1]
2025	593.8	[1]
2026	472.1	[1]
2027	350.4	[1]
2028	211.4	[1]
Thereafter	331.7	[1]
Total	2,489.6	[1]
Leasing & Services | Property Lease Guarantee [Member]
Future contractual minimum rental revenues
Guarantor Obligations, Maximum Exposure, Undiscounted	0.8
Leasing & Services | Other Third Parties [Member]
Future contractual minimum rental revenues
Remaining nine months of 2024	7.2
2025	7.5
2026	5.1
2027	1.1
2028	0.3
Thereafter	0.0
Total	$ 21.2

[1] Total contractual minimum rental revenues on operating leases relates to our wholly-owned and partially-owned subsidiaries and sub-lease rental revenues associated with the Leasing Group's operating lease obligations.