Repurchase Agreements - Summary of Repurchase Agreements Accounted as Secured Borrowings (Detail) $ in Thousands	Sep. 30, 2017 USD ($)
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	$ 63,081
Securities pledged for Repurchase Agreements, Total	79,216
Federal Agency Collateralized Mortgage Obligations [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	40,740
Federal Agency Mortgage-backed Pools [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	38,476
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase Agreements	63,081
Securities pledged for Repurchase Agreements, Total	79,216
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member] \| Federal Agency Collateralized Mortgage Obligations [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	40,740
Remaining Contractual Maturity of the Agreements, Overnight and Continuous [Member] \| Federal Agency Mortgage-backed Pools [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged for Repurchase Agreements, Total	$ 38,476

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No definition available.

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- Definition

Carrying value, as of the balance sheet date, of securities sold under agreements to repurchase where the transferor maintains effective control over the assets, accounting for them as secured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 10
-Section 55
-Paragraph 51
-URI http://asc.fasb.org/extlink&oid=77903054&loc=d3e101761-111710

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- Definition

Amount, before effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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