Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Income Taxes
Total income tax expense	$ 15.6	$ 16.3	$ 47.4	$ 52.2
Income tax expense as a percent of pre-tax income	33.80%	33.10%	33.40%	33.10%
Tax benefits related to the retroactive extension of the research and development credit and bonus depreciation		1.7
Current period tax provision that includes unfavorable impacts		$ 2.9
Statutory federal income tax rate (as a percent)	35.00%	35.00%	35.00%	35.00%