A valuation allowance for financing receivables that are expected to be uncollectible.

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

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

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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Amount of direct write-downs of financing receivables charged against the allowance.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 9

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-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

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Loans - Allowance for Loan Losses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				$ 16,234				$ 14,060	$ 16,234	$ 14,060	$ 12,615
Charge-offs									(3,182)	(5,630)	(5,190)
Recoveries									481	1,666	254
Provision for loan losses	282us-gaap_ProvisionForLoanAndLeaseLosses	1,038us-gaap_ProvisionForLoanAndLeaseLosses	1,501us-gaap_ProvisionForLoanAndLeaseLosses	1,019us-gaap_ProvisionForLoanAndLeaseLosses	1,247us-gaap_ProvisionForLoanAndLeaseLosses	846us-gaap_ProvisionForLoanAndLeaseLosses	3,115us-gaap_ProvisionForLoanAndLeaseLosses	930us-gaap_ProvisionForLoanAndLeaseLosses	3,840us-gaap_ProvisionForLoanAndLeaseLosses	6,138us-gaap_ProvisionForLoanAndLeaseLosses	6,381us-gaap_ProvisionForLoanAndLeaseLosses
Allowances for loan losses, Ending Balance	17,373				16,234				17,373	16,234	14,060
Commercial, Industrial, and Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				8,212				4,940	8,212	4,940	4,511
Charge-offs									(618)	(958)	(2,871)
Recoveries									1	7	45
Provision for loan losses									(481)	4,223	3,255
Allowances for loan losses, Ending Balance	7,114				8,212				7,114	8,212	4,940
Commercial Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				3,536				4,697	3,536	4,697	4,470
Charge-offs									(50)	(1,931)	(401)
Recoveries									210	1,430	0
Provision for loan losses									1,614	(660)	628
Allowances for loan losses, Ending Balance	5,310				3,536				5,310	3,536	4,697
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				2,450				2,466	2,450	2,466	1,991
Charge-offs									(436)	(467)	(304)
Recoveries									41	5	1
Provision for loan losses									424	446	778
Allowances for loan losses, Ending Balance	2,479				2,450				2,479	2,450	2,466
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				1,763				1,699	1,763	1,699	1,404
Charge-offs									(1,744)	(1,919)	(1,279)
Recoveries									93	114	91
Provision for loan losses									2,093	1,869	1,483
Allowances for loan losses, Ending Balance	2,205				1,763				2,205	1,763	1,699
Credit Cards [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				66				83	66	83	71
Charge-offs									(78)	(97)	(78)
Recoveries									25	16	18
Provision for loan losses									58	64	72
Allowances for loan losses, Ending Balance	71				66				71	66	83
Overdrafts [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowances for loan losses, Beginning Balance				207				175	207	175	168
Charge-offs									(256)	(258)	(257)
Recoveries									111	94	99
Provision for loan losses									132	196	165
Allowances for loan losses, Ending Balance	$ 194				$ 207				$ 194	$ 207	$ 175