Share-Based Compensation (Details 8) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Additional disclosures
Compensation cost	$ 10.0	$ 11.4	$ 13.1
Non-employee Board of Director's Plan
Share-based compensation disclosures
Percentage of Director's annual retainer paid in stock instead of cash	50.00%
Percentage of Director's committee chair fees paid in stock instead of cash	100.00%
Number of Units
Balance at the beginning of the period (in shares)	269,315	246,519	221,410
Granted (in shares)	24,668	19,770	21,710
Distributed (in shares)	(11,296)
Dividend equivalents (in shares)	4,749	3,026	3,399
Balance at the end of the period (in shares)	287,436	269,315	246,519
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 32.25	$ 30.06	$ 27.10
Granted (in dollars per share)	42.80	59.47	53.53
Distributed (in dollars per share)	31.79
Dividend equivalents (in dollars per share)	0.00	0.00	0.00
Balance at the end of the period (in dollars per share)	$ 35.48	$ 32.25	$ 30.06
Additional disclosures
Shares vesting period	1 year
Compensation cost	$ 1.1	$ 1.2	$ 1.2
Unvested stock option cost	$ 0.3
Unvested stock option weighted average remaining life	3 months 18 days
Non-employee Board of Director's Plan | Every 3 months
Share-based compensation disclosures
Percentage of units vests following the grant date	25.00%
Non-employee Board of Director's Plan | 1/4 of the units
Share-based compensation disclosures
Stock vesting period with reference to service term	3 months
Non-employee Board of Director's Plan | Minimum
Share-based compensation disclosures
Percentage of Director's annual retainer paid in stock instead of cash	50.00%