Stock-based Compensation - Schedule of Fair Value at the Date of Grant (Detail)	9 Months Ended
	Jun. 30, 2015 shares
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
Fiscal 2015 (2015 - 2017) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Shares	8,440
Target Shares	42,199
Maximum Shares	84,398