Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to retained earnings	$ 865.1		$ 889.8
Impact of Change | Retained Earnings | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to retained earnings			$ 2.4
Production, distribution, and editorial
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component		$ 0.8
Selling, General, and Administrative Expenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	$ 3.9	(0.2)
Nonoperating Income (Expense)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component		(0.6)
Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount reclassified out of financing activities		0.8
Amount reclassified into operating activities		$ 0.8