Leases (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) tankContainer railcar	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) tankContainer
Operating Leased Assets [Line Items]
Number of railcars received | tankContainer	728		21
Lessee, Lease, Number of Railcars Leased | railcar	4,432,000,000
Direct Financing Lease, Lease Income	$ 13.5	$ 12.6	$ 9.8
Operating Lease, Lease Income, Lease Payments	1,263.5	1,145.1	1,058.3
Operating Lease, Variable Lease Income	104.1	93.7	86.5
Operating Lease, Lease Income	1,367.6	1,238.8	1,144.8
Lease Income	1,381.1	1,251.4	$ 1,154.6
Total contractual lease payments receivable	160.0	171.8
Estimated unguaranteed residual value of leased assets	17.2	17.2
Unearned income	(58.9)	(52.6)
Finance leases	$ 118.3	$ 136.4