Restructuring Accruals (Severance and Related Benefit Costs by Segment) (Details) $ in Millions	Jun. 30, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Amount Accrued	$ 104.9
Total Amount Expected to be Incurred	107.4
National Media Acquisition
Restructuring Cost and Reserve [Line Items]
Amount Accrued	51.5
Total Amount Expected to be Incurred	52.5
Local Media Acquisition
Restructuring Cost and Reserve [Line Items]
Amount Accrued	0.9
Total Amount Expected to be Incurred	0.9
Unallocated Corporate
Restructuring Cost and Reserve [Line Items]
Amount Accrued	52.5
Total Amount Expected to be Incurred	$ 54.0