Summary of Significant Accounting Policies Lessor Accounting (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Renewal Term		5 years
Direct Financing Lease, Revenue		$ 0.0
Operating lease revenues		176.7	$ 163.6
Variable operating lease revenues		14.6	13.2
Interest income on sales-type lease receivables		0.2	$ 0.1
Profit recognized at sales-type lease commencement (1)	[1]	0.0
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Remainder of Fiscal Year		0.8
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Two		1.1
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Three		1.1
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Four		1.1
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, Year Five		1.1
Sales-Type and Direct Financing Leases, Lease Receivable, to be Received, after Year Five		10.1
Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received		15.3
Less: Unearned interest income		(4.8)
Net investment in sales-type leases (1)	[2]	10.5
Railcar Leasing and Management Services Group [Member]
Lessor, Lease, Description [Line Items]
Remaining nine months of 2023	[3]	480.8
2024	[3]	533.8
2025	[3]	424.1
2026	[3]	312.9
2027	[3]	219.5
Thereafter	[3]	318.5
Total	[3]	$ 2,289.6
Minimum | Railcar Leasing and Management Services Group [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Term of Contract		1 year
Maximum | Railcar Leasing and Management Services Group [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Term of Contract		10 years

[1] Included in gains on dispositions of property – lease portfolio sales on our Consolidated Statements of Operations.

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

[3] 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.