v3.25.2
Property, Plant, and Equipment - Components of property, plant, and equipment (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 $ 9,963.2 $ 9,751.1
Less: accumulated depreciation (2,876.4) (2,763.0)
Property, Plant and Equipment, Net 7,086.8 6,988.1
Railcars on Lease [Member]    
Property, Plant and Equipment, Net [Abstract]    
Property, Plant and Equipment, Net 6,734.7 6,631.6
Railcars on Lease [Member] | Intersegment Eliminations [Member]    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 [1] (1,081.3) (1,069.8)
Property, Plant and Equipment, Net (728.5) (732.5)
Negative Accumulated Depreciation PP&E- Deferred Profit 352.8 337.3
Wholly-owned subsidiaries | Railcars on Lease [Member] | Operating Segments [Member]    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 7,934.1 7,715.0
Less: accumulated depreciation (1,861.1) (1,766.9)
Property, Plant and Equipment, Net 6,073.0 5,948.1
Partially-owned subsidiaries | Railcars on Lease [Member] | Operating Segments [Member]    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 2,236.0 2,233.1
Less: accumulated depreciation (845.8) (817.1)
Property, Plant and Equipment, Net 1,390.2 1,416.0
Operating & Administrative Assets [Member]    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 874.4 872.8
Less: accumulated depreciation (522.3) (516.3)
Property, Plant and Equipment, Net 352.1 356.5
Operating & Administrative Assets [Member] | Land    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 16.1 16.3
Operating & Administrative Assets [Member] | Buildings and improvements    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 405.6 403.2
Operating & Administrative Assets [Member] | Machinery and other    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 436.3 441.8
Operating & Administrative Assets [Member] | Construction in progress    
Property, Plant and Equipment, Net [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiaries of $1,923.6 and $1,920.5 $ 16.4 $ 11.5
[1] Includes deferred profit related to new railcar additions, sustainable railcar conversions, railcar modifications, and other betterments. The deferred profit is subsequently eliminated in consolidation.