Goodwill and Intangible Assets - Schedule of Acquired Intangible Assets, Other than Goodwill (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,296	$ 8,186
Accumulated Amortization	6,936	6,402
Net Carrying Amount	1,360	1,784
MSRs [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,022	912
Accumulated Amortization	302	250
Net Carrying Amount	720	662
Core deposit intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,274	7,274
Accumulated Amortization	6,634	6,152
Net Carrying Amount	$ 640	$ 1,122

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.

No definition available.

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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