Goodwill and Other Intangible Assets - Components of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 23,956	$ 18,478
Accumulated Amortization and Fair Value Adjustments	11,776	10,300
Net Carrying Amount	12,180us-gaap_FiniteLivedIntangibleAssetsNet	8,178us-gaap_FiniteLivedIntangibleAssetsNet
Customer Related Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	13,397	7,513
Accumulated Amortization and Fair Value Adjustments	6,726	4,854
Net Carrying Amount	6,671	2,659
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,559	10,965
Accumulated Amortization and Fair Value Adjustments	5,050	5,446
Net Carrying Amount	$ 5,509	$ 5,519

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

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=26713463&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.

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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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