Summary of Significant Accounting Policies Lessor Accounting (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Renewal Term		5 years		5 years
Direct Financing Lease, Revenue				$ 0.0
Operating lease revenues		$ 212.6	$ 194.5	622.4	$ 582.3
Variable operating lease revenues		15.7	14.7	50.2	49.2
Interest income on sales-type lease receivables		0.3	0.2	0.7	0.5
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Remainder of Fiscal Year		0.5		0.5
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Two		2.0		2.0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Three		2.0		2.0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Four		2.0		2.0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Five		2.0		2.0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, after Year Five		17.6		17.6
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received		26.1		26.1
Less: Unearned interest income		(8.0)		(8.0)
Other Assets [Member]
Lessor, Lease, Description [Line Items]
Net investment in sales-type leases (1)	[1]	18.1		18.1
Railcar Leasing and Services Group [Member]
Lessor, Lease, Description [Line Items]
Remaining three months of 2025	[2]	206.3		206.3
2026	[2]	733.1		733.1
2027	[2]	589.8		589.8
2028	[2]	417.4		417.4
2029	[2]	281.5		281.5
Thereafter	[2]	538.1		538.1
Total	[2]	2,766.2		2,766.2
Railcar Leasing and Services Group [Member] | Operating Segments [Member] | Sales of Leased Railcars [Domain]
Lessor, Lease, Description [Line Items]
Profit recognized at sales-type lease commencement (1)	[3]	$ 0.0	$ 0.0	$ 1.0	$ 0.0
Minimum | Railcar Leasing and Services Group [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Term of Contract		1 year		1 year
Maximum | Railcar Leasing and Services Group [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Term of Contract		10 years		10 years

[1] Included in other assets in our Consolidated Balance Sheets

[2] 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.

[3] Included in gains on dispositions of other property on our Consolidated Statements of Operations.