Revenues - Commercial Vehicle Distribution and Other (Details) - Commercial Vehicle Distribution and Other - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Total revenues	$ 146.0		$ 304.5
Penske Commercial Vehicles Australia
Revenues
Total revenues	61.7		119.2
Penske Power Systems
Revenues
Total revenues	83.3		183.5
Other
Revenues
Total revenues	$ 1.0		$ 1.8
Without Adoption of ASC 606
Revenues
Total revenues		$ 114.2		$ 227.2
Without Adoption of ASC 606 | Penske Commercial Vehicles Australia
Revenues
Total revenues		57.8		120.9
Without Adoption of ASC 606 | Penske Power Systems
Revenues
Total revenues		55.2		104.2
Without Adoption of ASC 606 | Other
Revenues
Total revenues		$ 1.2		$ 2.1