Restructuring Accrual - Severance and Related Benefit Costs by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Amount accrued in the period	$ 1.4	$ 2.3	$ 14.3	$ 16.0
Total amount expected to be incurred	14.3		14.3
Operating Segments | National Media
Restructuring Cost and Reserve [Line Items]
Amount accrued in the period	1.3	1.7	6.4	10.5
Total amount expected to be incurred	6.4		6.4
Operating Segments | Local Media
Restructuring Cost and Reserve [Line Items]
Amount accrued in the period	0.1	0.0	7.3	2.4
Total amount expected to be incurred	7.3		7.3
Unallocated Corporate
Restructuring Cost and Reserve [Line Items]
Amount accrued in the period	0.0	$ 0.6	0.6	$ 3.1
Total amount expected to be incurred	$ 0.6		$ 0.6