Derivatives and Hedging Activities - Summary of Fair Value of Company's Derivative Financial Instruments (Detail) - Derivatives Not Designated as Hedging Instruments [Member] $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($) Transaction
Other Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 21
Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability Derivatives, Fair Value	$ 25
Interest Rate Products [Member]
Derivatives Fair Value [Line Items]
Number of Transactions \| Transaction	2
Notional Amount	$ 2,480
Interest Rate Products [Member] \| Other Assets [Member]
Derivatives Fair Value [Line Items]
Asset Derivatives, Fair Value	21
Interest Rate Products [Member] \| Other Liabilities [Member]
Derivatives Fair Value [Line Items]
Liability Derivatives, Fair Value	$ 25

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Number of transactions.

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No definition available.

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Fair value, before effects of master netting arrangements, of a 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. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Section 50
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959

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Fair value, before effects of master netting arrangements, of a financial liability or 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. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
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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

No definition available.

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