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Fair Value of Financial Instruments - Schedule of Quantitative Information about Level 3 Fair Value Measurements (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2019 | Jun. 30, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | $ 1,234,121 | $ 718,119
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | 3,975 | 3,878
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | 3,157 | 3,071
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Non-Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | 791 | 791
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Commercial Business [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | 27 | 16
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | 3,975 | 3,878
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | $ 3,157 | $ 3,071
Valuation Techniques | [1] | Market valuation of underlying collateral |
Unobservable Input | [2] | Adjustments to reflect current conditions/selling costs |
Weighted Average |  | 7.29% | 7.03%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Non-Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | $ 791 | $ 791
Valuation Techniques | [1] | Market valuation of underlying collateral |
Unobservable Input | [2] | Adjustments to reflect current conditions/selling costs |
Weighted Average |  | 10.52% | 10.08%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Commercial Business [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Assets, Fair Value |  | $ 27 | $ 16
Valuation Techniques | [1] | Market valuation of underlying collateral |
Unobservable Input | [2] | Adjustments to reflect current conditions/selling costs |
Weighted Average |  | 8.91% | 9.36%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Minimum [Member] | Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 6.00% | 6.00%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Minimum [Member] | Non-Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 10.00% | 10.00%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Minimum [Member] | Commercial Business [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 8.00% | 9.00%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Maximum [Member] | Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 8.00% | 8.00%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Maximum [Member] | Non-Residential Mortgage [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 11.00% | 11.00%
Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member] | Market Valuation of Underlying Collateral [Member] | Adjustments to Reflect Current Conditions or Selling Costs [Member] | Maximum [Member] | Commercial Business [Member] |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] |  |  |
Range |  | 9.00% | 10.00%
[1] | The fair value of impaired loans is generally determined based on an independent appraisal of the fair value of a loan’s underlying collateral.
[2] | The fair value basis of impaired loans is adjusted to reflect management’s estimates of selling costs including, but not necessarily limited to, real estate brokerage commissions and title transfer fees

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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