Derivatives And Hedging Activities - Schedule of Pre-Tax Net Gains (Losses) of Cash flow Hedges (Detail) - Designated as Hedging Instrument [Member] - Cash Flow Hedges of Interest Rate Risk [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in OCI on Derivative (Effective Portion)	$ 40	$ 1,092
Gain Reclassified from Accumulated OCI into Income (Effective Portion)	5
(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		(6)
Interest Rate Products [Member]
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in OCI on Derivative (Effective Portion)	40	1,092
Interest Rate Products [Member] | Interest Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Gain Reclassified from Accumulated OCI into Income (Effective Portion)	$ 5
(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)		$ (6)