Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Stock-Based Compensation (Additional Textual) [Abstract]
Maximum period of achievement of performance goals to earn performance units	3 years
Minimum performance period of individual required to earn performance units	3 years
Stock Option [Member]
Stock-Based Compensation (Textual) [Abstract]
Compensation expense related to stock option	$ 3.2	$ 4.3	$ 6.2
Unrecognized compensation cost	$ 2.1
Unrecognized compensation costs, weighted average period	2 years 7 months
Weighted average fair value of options granted	$ 10.16	$ 13.76	$ 13.53
Fair value of options vested	$ 7.6	$ 5.1	$ 5.2
Tax benefits resulting from stock-based compensation deductions in excess of amounts reported for financial reporting purposes	1.3	6.0	4.2
Cash received from the exercise of capital stock option	11.7	20.6	12.5
Tax benefit from the exercise of capital stock option	2.0	4.6	2.8
Total Intrinsic value of options exercised	5.3	14.8	8.3
Restricted Stock Units - Time Vesting Performance Vesting [Member]
Stock-Based Compensation (Textual) [Abstract]
Compensation expense related to stock option	13.5	$ 13.1	$ 15.2
Unrecognized compensation cost	$ 12.5
Unrecognized compensation costs, weighted average period	2 years 6 months 10 days