Accounting for Share-Based Compensation 5 (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2012 Three Year PSUs Incentive Plan - 2010 Fiscal Year [Member]	Jun. 30, 2012 Three Year PSUs Incentive Plan - 2010 Fiscal Year [Member] Unrestricted Shares [Member]	Jun. 30, 2011 Three Year PSUs Incentive Plan - 2009 Fiscal Year [Member]	Jun. 30, 2011 Three Year PSUs Incentive Plan - 2009 Fiscal Year [Member] Unrestricted Shares [Member]
Summary of 3-year PSUs under the fiscal year 2010 and 2009 grant in first quarter of fiscal years 2013 and 2012
Performance Period	3 years		3 years
Unrestricted Shares		0.2		0.2
Weighted Average Grant Date Fair Value		$ 26.39		$ 24.68