Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Income Taxes
Total income tax expense	$ 16.3	$ 18.8	$ 52.2	$ 46.0
Income tax expense as a percent of pre-tax income	33.10%	36.30%	33.10%	36.30%
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