Purchase Commitments (Details) $ in Millions	Sep. 30, 2024 USD ($)
Capital Addition Purchase Commitments Total Revenue Equipment [Member]
Long-term Purchase Commitment [Line Items]
Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year	$ 203.8
Purchase Obligation, to be Paid, Year One	203.8
Purchase Obligation, to be Paid, Year Two	0.0
Purchase Obligation, to be Paid, Year Three	0.0
Purchase Obligation, Due in Fourth and Fifth Year	0.0
Purchase Obligation, Due after Fifth Year	0.0
Capital Addition Purchase Commitments of Tractors [Member]
Long-term Purchase Commitment [Line Items]
Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year	163.8
Capital Addition Purchase Commitments Non revenue equipment [Member]
Long-term Purchase Commitment [Line Items]
Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year	50.3
Purchase Obligation, to be Paid, Year One	50.3
Purchase Obligation, Due in Second and Third Year	65.0
Purchase Obligation, Due in Fourth and Fifth Year	5.3
Purchase Obligation, Due after Fifth Year	$ 0.2