Employee Stock Plans (Stock Option And RSU Transactions) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2013
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding, September 30, 2012, Stock Option	33.1
Granted, Stock Option	3.3
Options exercised, Stock Option	(8.5)
Forfeited/expired, Stock Option	(0.9)
Options outstanding, March 31, 2013, Stock Option	27.0
Total unrecognized stock-based compensation expense, net of estimated forfeitures, as of March 31, 2013	$ 46.7
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested RSUs, September 30, 2012, RSUs	7.3
Granted, RSUs	3.0
RSUs vested, RSUs	(3.4)
Forfeited/expired, RSUs	(0.6)
Nonvested RSUs, March 31, 2013, RSUs	6.3
Total unrecognized stock-based compensation expense, net of estimated forfeitures, as of March 31, 2013	$ 128.6