Accounting for Share-Based Compensation 6 (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Sales Retention Equity Program - 2012 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Performance Period	1 year
Sales Retention Equity Program - 2011 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Performance Period		1 year
Restricted Stock Awards [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares	3.5	3.5
Weighted Average Grant Date Fair Value	$ 26.23	$ 24.66
Restricted Stock Awards [Member] | Sales Retention Equity Program - 2012 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares	0.2
Weighted Average Grant Date Fair Value	$ 26.39
Restricted Stock Awards [Member] | Sales Retention Equity Program - 2011 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares		0.3
Weighted Average Grant Date Fair Value		$ 24.68
Restricted Stock Units [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares	0.7	0.6
Weighted Average Grant Date Fair Value	$ 24.30	$ 24.27
Restricted Stock Units [Member] | Sales Retention Equity Program - 2012 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares	0.1
Weighted Average Grant Date Fair Value	$ 23.41
Restricted Stock Units [Member] | Sales Retention Equity Program - 2011 Fiscal Year [Member]
Summarizes the RSAs and RSUs granted under Sales Retention Equity Programs
Shares		0.1
Weighted Average Grant Date Fair Value		$ 24.09