Acquisitions (Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions				12 Months Ended
	Jan. 31, 2018	Apr. 21, 2017	Dec. 07, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Goodwill				$ 1,915.8	$ 907.5	$ 883.2
Time, Inc.
Business Acquisition [Line Items]
Cash	$ 3,226.2
Fair value of total consideration transferred	3,226.8
Cash and cash equivalents	399.9
Accounts receivable	290.9
Inventory	22.8
Assets held-for-sale	1,006.1
Other current assets	60.0
Total current assets	1,779.7
Property, plant, and equipment	300.8
Other assets	98.0
Intangible assets	1,146.8
Total identifiable assets acquired	3,325.3
Accounts payable	140.0
Accrued liabilities	195.6
Current portion of unearned revenues	192.1
Liabilities associated with assets held-for-sale	315.7
Total current liabilities	843.4
Unearned revenues	41.7
Deferred income taxes	172.2
Other noncurrent liabilities	104.4
Total liabilities assumed	1,161.7
Total identified net assets	2,163.6
Goodwill	1,063.2
Net assets acquired	$ 3,226.8
FY 2017 Acquisition
Business Acquisition [Line Items]
Cash			$ 13.4
Fair value of total consideration transferred			21.1	0.0	2.6
Peachtree TV
Business Acquisition [Line Items]
Cash		$ 70.0
Peachtree TV and FY 2017 Acquisition
Business Acquisition [Line Items]
Cash					81.8
Payment in escrow					1.6
Contingent consideration arrangements					7.7
Fair value of total consideration transferred					91.1
Intangible assets					66.4
Total identifiable assets acquired					90.2
Total liabilities assumed					23.4
Total identified net assets					66.8
Goodwill					24.3
Net assets acquired					91.1
National Media Acquisition
Business Acquisition [Line Items]
Goodwill				1,800.0	826.9	814.4
National Media Acquisition | FY 2017 Acquisition
Business Acquisition [Line Items]
Cash					11.8
Payment in escrow					1.6
Contingent consideration arrangements			$ 7.7		7.7
Fair value of total consideration transferred					21.1
Intangible assets					8.6
Total identifiable assets acquired					8.6
Total liabilities assumed					0.0
Total identified net assets					8.6
Goodwill					12.5
Net assets acquired					21.1
Local Media Acquisition
Business Acquisition [Line Items]
Goodwill				$ 115.8	80.6	$ 68.8
Local Media Acquisition | Peachtree TV
Business Acquisition [Line Items]
Cash					70.0
Payment in escrow					0.0
Contingent consideration arrangements					0.0
Fair value of total consideration transferred					70.0
Intangible assets					57.8
Total identifiable assets acquired					81.6
Total liabilities assumed					23.4
Total identified net assets					58.2
Goodwill					11.8
Net assets acquired					$ 70.0