Description Of Business And Basis Of Presentation Fiscal Period (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2013	Mar. 31, 2012
Fiscal Period
Current and prior years fiscal period (in weeks)			P26W	P26W	P52W	P52W
Current and prior years fiscal quarter period (in weeks)	P13W	P13W
Minimum
Fiscal Period
Fiscal year (in weeks)					P52W
Maximum
Fiscal Period
Fiscal year (in weeks)					P53W