Quarterly Financial Data (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended			9 Months Ended
	Mar. 31, 2012	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010	Dec. 31, 2011 Cost Of Sales [Member]
Quarterly Financial Data [Line Items]
Errors primarily understated	$ 4.2		$ 10.4	$ 8.0	$ 0.8
Net income partially offset by the correction of an error	$ 21.5	$ 24.9
Earnings per share partially reduced by the correction of an error	$ 0.03	$ 0.03