Capital Purchase Program - Fair Value of Warrant (Detail) (USD $)	12 Months Ended
Dec. 31, 2013
Equity [Abstract]
Contractual term	10 years
Exercise price	$ 31.53
Estimated fair value of company stock	$ 29.14
Expected life	10 years
Risk-free rate over expected life of the warrant	2.36%
Expected volatility	28.40%
Expected dividend yield	3.85%

Contractual term.

No definition available.

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- Definition

Fair value per share preferred stock.

+ References

No definition available.

+ Details

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- Details

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- Definition

Agreed upon price for the exchange of the underlying asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

+ Details

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- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

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- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

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