Stock-Based Compensation Plans - Schedule of Fair Value at the Date of Grant (Detail)	12 Months Ended
	Sep. 30, 2014
Fiscal 2012 (2012 - 2014) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Shares	12,499
Target Shares	62,497
Maximum Shares	98,093
Fiscal 2013 (2013 - 2015) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Shares	8,551
Target Shares	42,753
Maximum Shares	85,506
Fiscal 2014 (2014 - 2016) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Shares	7,861
Target Shares	39,303
Maximum Shares	78,606