Fair Value Measurements (Schedule of changes in fair value of level 3 contingent consideration) (Details) - Level 3 - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Measured at fair value on recurring basis | Corporate airplanes held-for-sale
Fair Value Assets [Roll Forward]
Balance at beginning of year	$ 1.9	$ 2.8
Fair value adjustment of corporate airplanes	0.0	0.9
Sale	(1.9)	0.0
Balance at end of year	0.0	1.9
Measured at fair value on recurring basis | Investment in Next Issue Media
Fair Value Assets [Roll Forward]
Balance at beginning of year	11.0
Additions due to investment and acquisition	3.3
Equity method investment losses	(3.6)
Impairment	9.3
Sale	(1.4)
Balance at end of year	0.0	11.0
Measured at fair value on recurring basis | Contingent consideration
Fair Value Liabilities [Roll Forward]
Balance at beginning of year	25.4	34.2	$ 56.6
Accrual on Time’s opening balance sheet	1.1	0.0
Additions due to acquisitions	0.0	7.7
Payments	(5.1)	(10.6)
Fair value adjustment of contingent consideration	(4.8)	(19.5)
Balance at end of year	25.4	34.2	56.6
Measured at fair value on recurring basis | Lease guarantee
Fair Value Liabilities [Roll Forward]
Balance at beginning of year	11.9	0.0	0.0
Accrual on Time’s opening balance sheet	3.6	0.0
Issuance of new guarantees	9.2	0.0
Fair value adjustment of contingent consideration	(0.4)	0.0
Foreign currency exchange impact	(0.5)	0.0
Balance at end of year	11.9	0.0	$ 0.0
2018 Trademarks | Measured at fair value on nonrecurring basis
Fair Value Assets [Roll Forward]
Balance at beginning of year	55.7
Impairment	22.7
Balance at end of year	33.0	55.7
2017 Trademarks | Measured at fair value on nonrecurring basis
Fair Value Assets [Roll Forward]
Balance at beginning of year	$ 0.0	5.3
Impairment		5.3
Balance at end of year		$ 0.0