Other Real Estate Owned - Summary of Activity in Purchased Non-Covered Other Real Estate Owned (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Real Estate Owned, Disclosure of Detailed Components [Abstract]
Beginning balance	$ 4,276us-gaap_OtherRealEstateNonCovered
Loans transferred to other real estate owned	4,160
Acquired in acquisitions	8,864	5,623
Transfer from covered other real estate owned due to loss share expiration	1,226
Net gains (losses) on sale and write-downs	828
Sales proceeds	(3,769)	(1,347)
Ending balance	$ 15,585us-gaap_OtherRealEstateNonCovered	$ 4,276us-gaap_OtherRealEstateNonCovered

Other Real Estate Non Covered Net Gains Losses On Sale And Write Downs

No definition available.

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- Definition

Other Real Estate Non Covered Transfers Of Loans

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No definition available.

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- Definition

Carrying amount of other real estate not covered by loss sharing agreements not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations that may also be included in real estate owned. Excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure by banks.

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No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Additions of other real estate not covered by loss sharing agreements not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations that may also be included in real estate owned. Excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure by banks.

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No definition available.

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- Definition

Disposals of other real estate not covered by loss sharing agreements not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations that may also be included in real estate owned. Excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure by banks.

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No definition available.

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- Definition

Valuation adjustments made to other real estate not covered by loss sharing agreements not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations that may also be included in real estate owned. Excludes real estate assets taken in settlement of troubled loans through surrender or foreclosure by banks.

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No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Details

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