Loans and Allowance for Credit Losses - Troubled Debt Restructuring is 90 Days or More Past Due (Detail) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015 USD ($) Contract	Jun. 30, 2014 USD ($) Contract	Jun. 30, 2015 USD ($) Contract	Jun. 30, 2014 USD ($) Contract
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| Contract			2	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 56	$ 51
Troubled Debt Restructuring Number Of Contracts Ninety Days Past Due \| Contract	2	1
Financing Receivable, Modification, Subsequent Default, Recorded Investment	$ 56	$ 6
Residential real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| Contract			2	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment			$ 56	$ 51
Troubled Debt Restructuring Number Of Contracts Ninety Days Past Due \| Contract	2	1
Financing Receivable, Modification, Subsequent Default, Recorded Investment	$ 56	$ 6

Financing Receivable, Modification, Subsequent Default, Recorded Investment

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- Definition

Troubled debt restructuring number of contracts 90 days past due.

+ References

No definition available.

+ Details

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 34

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953682-111524

+ Details

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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- Definition

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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