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Derivative Instruments and Hedging Activities - Additional Information (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2019 USD ($) Instrument	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) Instrument	Jun. 30, 2019 USD ($)
Loan Origination Commitments [Member]
Derivative [Line Items]
Pipeline of loans held-for-sale	$ 65,900		$ 65,900	$ 46,200
Counter Party [Member]
Derivative [Line Items]
Financial collateral not included as offsetting amounts	150		150
Interest Expense [Member]
Derivative [Line Items]
Estimated cash flow hedge gain (loss) to be reclassified in next twelve months			$ (1,200)
Cash Flow Hedges [Member]
Derivative [Line Items]
Reclassifications to interest expense	$ 1,371	$ 1,236
Cash Flow Hedges [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Number of interest rate derivative instruments held | Instrument	15		15
Derivative, notional amount	$ 1,000,000		$ 1,000,000
Cash Flow Hedges [Member] | Interest Rate Swaps [Member] | Interest Expense [Member]
Derivative [Line Items]
Reclassifications to interest expense	$ 1,371	$ 1,236

X

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Nominal or face amount used to calculate payment on derivative.

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Number of interest rate derivative instruments held by the entity at the reporting date.

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