Additional Detail of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Modifications [Line Items]
Outstanding Record Investment Pre-Modification	$ 72	$ 249
Outstanding Record Investment Post-Modification	72	249
Number of loans	2	3
Interest income Recognized	13	29	100
Commercial installment
Financing Receivable, Modifications [Line Items]
Outstanding Record Investment Pre-Modification	0	0
Outstanding Record Investment Post-Modification	0	0
Number of loans	0	0
Interest income Recognized	0	0
Commercial real estate
Financing Receivable, Modifications [Line Items]
Outstanding Record Investment Pre-Modification	0	0
Outstanding Record Investment Post-Modification	0	0
Number of loans	0	0
Interest income Recognized	0	31	77
Consumer real estate
Financing Receivable, Modifications [Line Items]
Outstanding Record Investment Pre-Modification	72	249
Outstanding Record Investment Post-Modification	72	249
Number of loans	2	3
Interest income Recognized	0	30	12
Consumer installment
Financing Receivable, Modifications [Line Items]
Outstanding Record Investment Pre-Modification	0	0
Outstanding Record Investment Post-Modification	0	0
Number of loans	0	0
Interest income Recognized	$ 0	$ 0

Financing Receivable, Modifications, Number of Contracts, During Period

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- Definition

Financing Receivable, Modifications, Post-Modification Recorded Investment During Period

+ References

No definition available.

+ Details

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- Definition

Financing Receivable, Modifications, Pre-Modification Recorded Investment During Period

+ References

No definition available.

+ Details

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524

+ Details

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