Average Recorded Investment and Interest Income Recognized on Impaired Loans Excluding Purchased Credit Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment	$ 8,588	$ 24,126	$ 8,976	$ 17,343
Impaired loans with a related allowance, Average Recorded Investment	16,563	11,403	18,454	13,373
Total impaired loans, Average Recorded Investment	25,151	35,529	27,430	30,716
Impaired loans with no related allowance, Interest Income Recognized	159	315	272	766
Impaired loans with a related allowance, Interest Income Recognized	60	4	190	197
Total impaired loans, Interest Income Recognized	219	319	462	963
Commercial Loans \| Construction Development And Other Land
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		6,828		4,511
Impaired loans with a related allowance, Average Recorded Investment		1,095		1,882
Impaired loans with no related allowance, Interest Income Recognized		211		254
Impaired loans with a related allowance, Interest Income Recognized				117
Commercial Loans \| Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment	293	1,903	293	1,251
Impaired loans with a related allowance, Average Recorded Investment	3,640	3,592	4,399	3,350
Impaired loans with no related allowance, Interest Income Recognized	17		29	11
Impaired loans with a related allowance, Interest Income Recognized	3		50
Commercial Loans \| Multi-family Residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		37		36
Impaired loans with a related allowance, Average Recorded Investment	5,586		5,595	188
Impaired loans with no related allowance, Interest Income Recognized		1		3
Impaired loans with a related allowance, Interest Income Recognized	21		43	7
Commercial Loans \| Single-family Non-owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		2,281	210	1,561
Impaired loans with a related allowance, Average Recorded Investment	369	1,098	371	1,413
Impaired loans with no related allowance, Interest Income Recognized		14	1	93
Impaired loans with a related allowance, Interest Income Recognized	1		2	3
Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment	6,379	9,068	6,149	7,512
Impaired loans with a related allowance, Average Recorded Investment	4,427	2,011	4,413	2,383
Impaired loans with no related allowance, Interest Income Recognized	89	84	125	296
Impaired loans with a related allowance, Interest Income Recognized	25		50	26
Commercial Loans \| Farmland Loan
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment	360	361	362	225
Impaired loans with no related allowance, Interest Income Recognized	11		22	9
Consumer Real Estate \| Home Equity Lines
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		708	133	503
Impaired loans with a related allowance, Average Recorded Investment		230	115	226
Impaired loans with no related allowance, Interest Income Recognized			2	25
Impaired loans with a related allowance, Interest Income Recognized			1	3
Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment	1,556	2,867	1,829	1,707
Impaired loans with a related allowance, Average Recorded Investment	2,541	3,377	3,561	3,931
Impaired loans with no related allowance, Interest Income Recognized	42		93	70
Impaired loans with a related allowance, Interest Income Recognized	10	4	44	41
Consumer Real Estate \| Owner occupied construction
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		61		31
Impaired loans with no related allowance, Interest Income Recognized		5		5
Consumer and Other \| Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Average Recorded Investment		$ 12		$ 6

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ 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)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5258-111524

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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.

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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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