Loans and Allowance - Allowance for Credit Losses and Loan Portfolio by Loan Segment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Individually evaluated for impairment	$ 1,354	$ 4,243
Allowance balances - Collectively evaluated for impairment	66,287	65,123
Allowance balances - Loans Acquired with Deteriorated Credit Quality	229
Total Allowance for Loan Losses	67,870	69,366	70,898	82,977
Loan balances - Individually evaluated for impairment	42,067	68,099
Loan balances - Collectively evaluated for impairment	3,511,501	2,821,358
Loan balances - Loans Acquired with Deteriorated Credit Quality	78,841	12,752
Loans	3,632,409	2,902,209
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Individually evaluated for impairment	585	1,628
Allowance balances - Collectively evaluated for impairment	26,493	24,285
Allowance balances - Loans Acquired with Deteriorated Credit Quality	98
Total Allowance for Loan Losses	27,176	25,913	17,731	32,508
Loan balances - Individually evaluated for impairment	10,240	14,190
Loan balances - Collectively evaluated for impairment	882,794	765,707
Loan balances - Loans Acquired with Deteriorated Credit Quality	7,548	1,710
Loans	900,582	781,607
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Individually evaluated for impairment	763	2,565
Allowance balances - Collectively evaluated for impairment	22,208	24,138
Allowance balances - Loans Acquired with Deteriorated Credit Quality	131
Total Allowance for Loan Losses	23,102	26,703	37,919	36,341
Loan balances - Individually evaluated for impairment	29,007	45,394
Loan balances - Collectively evaluated for impairment	1,690,285	1,309,912
Loan balances - Loans Acquired with Deteriorated Credit Quality	69,599	10,015
Loans	1,788,891	1,365,321
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Collectively evaluated for impairment	2,515	2,593
Total Allowance for Loan Losses	2,515	2,593	2,902	3,622
Loan balances - Collectively evaluated for impairment	69,783	75,748
Loans	69,783	75,748
Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Individually evaluated for impairment	6	50
Allowance balances - Collectively evaluated for impairment	15,071	14,107
Total Allowance for Loan Losses	15,077	14,157	12,343	10,408
Loan balances - Individually evaluated for impairment	2,820	8,515
Loan balances - Collectively evaluated for impairment	867,094	667,401
Loan balances - Loans Acquired with Deteriorated Credit Quality	1,694	1,027
Loans	871,608	676,943
Finance Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance balances - Collectively evaluated for impairment
Total Allowance for Loan Losses			3	98
Loan balances - Collectively evaluated for impairment	1,545	2,590
Loans	$ 1,545	$ 2,590

Loans and Leases Receivable

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- Definition

The balance of financing receivables that were acquired with deteriorated credit quality.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

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- Definition

The valuation allowance for financing receivables acquired with deteriorated credit quality.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance 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 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Name Accounting Standards Codification

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

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