Restructuring Accruals (Narrative) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017 USD ($)	Jun. 30, 2019 USD ($) employee	Jun. 30, 2018 USD ($) employee	Jun. 30, 2017 USD ($) employee
Restructuring Cost and Reserve [Line Items]
Number of employees affected by the plan | employee				215
Accruals		$ 87.4	$ 106.3
Restructuring charges	$ 3.1			$ 12.4
Reversal of excess accrual		6.0	0.8
Restructuring liability		66.5	107.6	8.7
Restructuring liability, current portion		48.4
Restructuring liability, noncurrent portion		18.1
Restructuring, business acquisition and integration charges
Restructuring Cost and Reserve [Line Items]
Manuscript and art inventory write-down			0.5	0.2
Employee Terminations
Restructuring Cost and Reserve [Line Items]
Accruals		56.3	104.9
Restructuring charges			104.9	11.9
Reversal of excess accrual		4.4	0.8	1.8
Restructuring liability		43.7	101.3	8.7
Other Exit Costs
Restructuring Cost and Reserve [Line Items]
Accruals		31.1	1.4
Other restructuring costs				0.3
Reversal of excess accrual		1.6	0.0
Restructuring liability		$ 22.8	$ 6.3	$ 0.0
Restructuring related to 2018 performance improvement plan
Restructuring Cost and Reserve [Line Items]
Number of employees affected by the plan | employee		300	1,800
Restructuring related to 2018 performance improvement plan | National media
Restructuring Cost and Reserve [Line Items]
Number of employees affected by the plan | employee		225
Restructuring related to 2018 performance improvement plan | Local media
Restructuring Cost and Reserve [Line Items]
Number of employees affected by the plan | employee		25