v3.26.3
Property, Plant, and Equipment - Components of property, plant, and equipment (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 $ 8,967.0 $ 9,258.3
Less: accumulated depreciation (2,573.3) (2,637.0)
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization 6,393.7 6,621.3
Railcars on Lease [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization 6,026.5 6,256.0
Railcars on Lease [Member] | Intersegment Eliminations [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 [1] (828.9) (926.6)
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization (556.4) (628.6)
Negative Accumulated Depreciation PP&E- Deferred Profit 272.5 298.0
Wholly-owned subsidiaries    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Net Book Value of Unpledged Equipment 798.8  
Wholly-owned subsidiaries | Secured Debt [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Debt Instrument, Collateral Amount 5,740.5  
Wholly-owned subsidiaries | Railcars on Lease [Member] | Operating Segments [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 8,901.7 8,668.5
Less: accumulated depreciation (2,318.8) (2,156.1)
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization 6,582.9 [2] 6,512.4
Partially-owned subsidiaries | Railcars on Lease [Member] | Operating Segments [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 0.0 620.5
Less: accumulated depreciation 0.0 (248.3)
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization 0.0 372.2
Operating & Administrative Assets [Member]    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 894.2 895.9
Less: accumulated depreciation (527.0) (530.6)
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization 367.2 365.3
Operating & Administrative Assets [Member] | Land    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 15.9 16.1
Operating & Administrative Assets [Member] | Buildings and improvements    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 401.5 408.4
Operating & Administrative Assets [Member] | Machinery and other    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 437.3 452.9
Operating & Administrative Assets [Member] | Construction in progress    
Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization [Abstract]    
Property, plant, and equipment, at cost, including partially-owned subsidiary of $— and $523.9 $ 39.5 $ 18.5
[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.
[2] The Leasing Group’s debt at September 30, 2026 consisted of non-recourse debt. As of September 30, 2026, Trinity’s wholly-owned subsidiaries included in the Leasing Group held equipment with a net book value of $5,740.5 million, which is pledged solely as collateral for Leasing Group debt held by those subsidiaries. The net book value of unpledged equipment at September 30, 2026 was $798.8 million. See Note 7 for more information regarding the Leasing Group's debt.