Financial Information about Industry Segments (Narrative) (Details) $ in Millions	12 Months Ended
	Jun. 30, 2018 USD ($) segment measure	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2
Number of principal financial measures | measure	2
Segment Reporting Information [Line Items]
Amortization of broadcast rights	$ 19.2	$ 17.6	$ 16.7
National Media Acquisition
Segment Reporting Information [Line Items]
Impairment of intangible assets and goodwill	$ (22.7)	$ (5.3)	$ (155.8)