Intangible Assets and Goodwill - Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	$ 794.3		$ 805.7
Intangible assets subject to amortization, accumulated amortization	(276.3)		(248.8)
Intangible assets subject to amortization, net amount	518.0		556.9
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	1,448.3		1,448.3
Intangible assets, net	1,966.3		2,005.2
Amortization expense	38.8	$ 4.7
Future amortization expense for intangible assets [Abstract]
Future amortization expense, fiscal 2019	155.0
Future amortization expense, fiscal 2020	140.3
Future amortization expense, fiscal 2021	86.9
Future amortization expense, fiscal 2022	41.0
Future amortization expense, fiscal 2023	39.0
Trademarks | National media
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	765.3		765.3
Internet domain names | National media
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	7.8		7.8
FCC licenses | Local media
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	675.2		675.2
Advertiser relationships | National media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	213.4		212.3
Intangible assets subject to amortization, accumulated amortization	(49.0)		(41.1)
Intangible assets subject to amortization, net amount	164.4		171.2
Advertiser relationships | Local media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	12.5		25.0
Intangible assets subject to amortization, accumulated amortization	(2.8)		(3.5)
Intangible assets subject to amortization, net amount	9.7		21.5
Publisher relationships | National media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	125.0		125.0
Intangible assets subject to amortization, accumulated amortization	(11.9)		(7.4)
Intangible assets subject to amortization, net amount	113.1		117.6
Partner relationships | National media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	95.0		95.0
Intangible assets subject to amortization, accumulated amortization	(10.6)		(6.6)
Intangible assets subject to amortization, net amount	84.4		88.4
Customer relationships | National media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	67.5		67.5
Intangible assets subject to amortization, accumulated amortization	(22.0)		(14.0)
Intangible assets subject to amortization, net amount	45.5		53.5
Other | National media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	22.0		22.0
Intangible assets subject to amortization, accumulated amortization	(12.8)		(11.9)
Intangible assets subject to amortization, net amount	9.2		10.1
Other | Local media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	1.7		1.7
Intangible assets subject to amortization, accumulated amortization	(0.9)		(0.8)
Intangible assets subject to amortization, net amount	0.8		0.9
Network affiliation agreements | Local media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	229.3		229.3
Intangible assets subject to amortization, accumulated amortization	(150.3)		(148.6)
Intangible assets subject to amortization, net amount	79.0		80.7
Retransmission agreements | Local media
Finite-Lived Intangible Assets [Line Items]
Intangible assets subject to amortization, gross amount	27.9		27.9
Intangible assets subject to amortization, accumulated amortization	(16.0)		(14.9)
Intangible assets subject to amortization, net amount	$ 11.9		$ 13.0