Loans and Loans Held for Sale - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013 Loans TDRs Property	Dec. 31, 2012 TDRs
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned income on loans	$ 1.3	$ 0.2
Loans held for sale		19.3
Percentage of commercial loans in total portfolio loans	73.00%	72.00%
Maximum concentration of commercial real estate and commercial construction portfolio in loans	9.00%	9.00%
Financial receivable trouble debt restructuring reclassified to accruing trouble debt restructuring status	6.9	0
Number of TDRs returned back to accruing status	6	0
Number of loan modified	11
Commitment to lend additional funds on TDRs	0
Minimum period of loan payment defaults following restructure for TDRs to be in default	90 days
Other real estate owned properties	8
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
New loans modified considered to be troubled debt restructuring	2.0	6.9
CRE and Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Combined percentage of commercial real estate and commercial construction in total commercial loans	68.00%	67.00%
Combined percentage of commercial real estate and commercial construction in total portfolio loans	49.00%	48.00%
Out-of-state exposure of combined portfolio	23.00%	19.00%
Percentage of total loans out-of-state	11.00%	9.00%
Out-of-state exposure of combined portfolio excluding contiguous states	7.90%	8.40%
Percentage of total loans out-of-state excluding contiguous states	3.90%	4.10%
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modified	6
Loans modified not considered to be troubled debt restructuring	6.4
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modified	2
Loans modified not considered to be troubled debt restructuring	0.6
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modified	1
Loans modified not considered to be troubled debt restructuring	0.9
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan modified	2
Loans modified not considered to be troubled debt restructuring	$ 1.1

Combined percentage of commercial real estate and commercial construction in commercial loans.

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- Definition

Combined percentage of commercial real estate and commercial construction in portfolio loans.

+ References

No definition available.

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- Definition

Commitment to lend additional funds.

+ References

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- Definition

Financial receivable trouble debt restructuring reclassified to accruing trouble debt restructuring status.

+ References

No definition available.

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- Definition

Financing receivable modifications new troubled debt restructuring

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Loans modified not considered to be troubled debt restructuring.

+ References

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Concentration of commercial real estate and commercial construction portfolio to total loans percentage.

+ References

No definition available.

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- Definition

Net loans out of state, percentage.

+ References

No definition available.

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- Definition

Net loans out of state percentage excluding contiguous states.

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No definition available.

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Number of loans modified not considered to be troubled debt restructuring.

+ References

No definition available.

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- Definition

Nonaccrual TDR returned to accruing TDR status.

+ References

No definition available.

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- Definition

Other real estate owned properties.

+ References

No definition available.

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- Definition

Out of state exposure of combined commercial real estate and commercial construction portfolio percentage.

+ References

No definition available.

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Out of state exposure of combined commercial real estate and commercial construction portfolio excluding contiguous states percentage.

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No definition available.

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- Definition

Percentage of commercial loans to total loan portfolio.

+ References

No definition available.

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- Definition

Minimum period of loan payment defaults following restructure for TDRs to be in default.

+ References

No definition available.

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- Definition

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 9

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- Definition

Amount of mortgage loans held for sale. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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-Publisher FASB

-Name Accounting Standards Codification

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-Glossary Permanent Investor

-URI http://asc.fasb.org/extlink&oid=6520390

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