v3.26.1
Contractual Maturities on Marketable Debt Securities (Detail) - Truck, Parts and Other
$ in Millions
Jun. 30, 2026
USD ($)
Amortized Cost Maturities:  
Within one year $ 641.4
One to five years 2,603.9
Six to ten years 5.9
More than ten years 4.9
Marketable debt securities, Cost 3,256.1
Fair Value Maturities:  
Within one year 642.5
One to five years 2,599.4
Six to ten years 5.9
More than ten years 5.0
Fair Value $ 3,252.8