Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Non-union pension settlement charge			$ 7.2	$ 0.0
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.1	$ 1.3	0.3	3.9
Interest cost	11.1	12.8	32.9	38.4
Expected return on plan assets	(15.0)	(14.8)	(45.2)	(44.4)
Amortization of prior service credit	(0.1)	0.0	(0.3)	0.0
Amortization of prior net pension loss	3.5	3.9	10.9	11.7
Settlement loss	7.2	0.0	7.2	0.0
Total periodic pension cost	6.8	$ 3.2	5.8	$ 9.6
Expected future benefit payments, remainder of the year	15.4		15.4
Contributions by employer			13.4
Operating Segments | YRC Freight | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-union pension settlement charge	$ 7.2		$ 7.2