Fair Value Measurements - Summary of Valuation Techniques and Significant Unobservable Inputs Used to Measure Level 3 Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2016	Sep. 30, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Property held for sale	$ 8,067	$ 8,112
Fair value, measurements, nonrecurring
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	1,020	6,911
Impaired loans	194,051	190,743
Fair value, measurements, nonrecurring \| Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned	1,020	6,911
Impaired loans	194,051	$ 190,743
Loan servicing rights	5,278
Property held for sale	$ 8,067
Fair value, measurements, nonrecurring \| Level 3 \| Loan servicing rights \| Discounted cash flows \| Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate (as a percent)	9.00%
Discount rate (as a percent)	9.50%
Fair value, measurements, nonrecurring \| Level 3 \| Loan servicing rights \| Discounted cash flows \| Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate (as a percent)	21.00%
Discount rate (as a percent)	16.00%
Fair value, measurements, nonrecurring \| Level 3 \| Loan servicing rights \| Discounted cash flows \| Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate (as a percent)	12.70%
Discount rate (as a percent)	11.90%

Impaired Loans Receivable, Fair Value Disclosure

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- Definition

Real Estate Acquired Through Foreclosure, Fair Value Disclosure

+ References

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- Definition

Amount of assets held-for-sale that are not part of a disposal group.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 15
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6390208&loc=d3e400-110220

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value.

+ References

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- Definition

Fair value of a liability representing servicing arrangements under which the estimated future revenue from contractually specified servicing fees, late charges, and other ancillary revenues are not expected to adequately compensate the servicer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122492-111745

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122625-111746

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