Railcar Leasing and Management Services Group - Future operating lease obligations and future contractual minimum rental revenues (Details) $ in Millions	Mar. 31, 2023 USD ($)
Future operating lease obligations
Remaining nine months of 2023	$ 15.0
2024	15.1
2025	13.4
2026	12.7
2027	12.2
Thereafter	60.2
Lessee, Operating Lease, Liability, to be Paid, Total	128.6
Railcar Leasing and Management Services Group [Member]
Future operating lease obligations
Remaining nine months of 2023	8.1
2024	7.0
2025	6.1
2026	5.8
2027	5.3
Thereafter	3.7
Lessee, Operating Lease, Liability, to be Paid, Total	36.0
Future contractual minimum rental revenues
Remaining nine months of 2023	480.8	[1]
2024	533.8	[1]
2025	424.1	[1]
2026	312.9	[1]
2027	219.5	[1]
Thereafter	318.5	[1]
Total	2,289.6	[1]
Railcar Leasing and Management Services Group [Member] | Railroad Transportation Equipment
Future operating lease obligations
Remaining nine months of 2023	8.0
2024	6.9
2025	6.1
2026	5.8
2027	5.3
Thereafter	3.7
Lessee, Operating Lease, Liability, to be Paid, Total	35.8
Railcar Leasing and Management Services Group [Member] | Building [Member]
Future operating lease obligations
Lessee, Operating Lease, Liability, to be Paid, Total	0.2
Railcar Leasing and Management Services Group [Member] | Property Lease Guarantee [Member]
Future contractual minimum rental revenues
Guarantor Obligations, Maximum Exposure, Undiscounted	1.2
Railcar Leasing and Management Services Group [Member] | Operating leases
Future contractual minimum rental revenues
Remaining nine months of 2023	7.2
2024	5.1
2025	3.6
2026	2.0
2027	0.5
Thereafter	0.1
Total	$ 18.5

[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.