Recorded Investment In Loans Considered To Be Impaired And Related Information On Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	$ 18,645		$ 18,645		$ 9,418
Impaired loans with a related allowance, Recorded Investment	11,018		11,018		13,784
Total impaired loans, Recorded Investment	29,663		29,663		23,202
Impaired loans with no related allowance, Unpaid Principal balance	24,075		24,075		9,906
Impaired loans with a related allowance, Unpaid Principal Balance	16,536		16,536		19,450
Total impaired loans, Unpaid Principal Balance	40,611		40,611		29,356
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	4,843		4,843		5,593
Total impaired loans, Related Allowance	4,843		4,843		5,593
Impaired loans with no related allowance, Average Recorded Investment	24,126	9,468	17,343	11,893
Impaired loans with a related allowance, Average Recorded Investment	11,403	16,435	13,373	16,893
Total impaired loans, Average Recorded Investment	35,529	25,903	30,716	28,786
Impaired loans with no related allowance, Interest Income Recognized	315	59	1,174	105
Impaired loans with a related allowance, Interest Income Recognized	4	256	216	404
Total impaired loans, Interest Income Recognized	319	315	1,390	509
Commercial Loans \| Construction Development And Other Land
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	4,347		4,347		2,916
Impaired loans with a related allowance, Recorded Investment	1,094		1,094
Impaired loans with no related allowance, Unpaid Principal balance	6,832		6,832		2,916
Impaired loans with a related allowance, Unpaid Principal Balance	1,094		1,094
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	164		164
Impaired loans with no related allowance, Average Recorded Investment	6,828	11	4,511	30
Impaired loans with a related allowance, Average Recorded Investment	1,095	111	1,882	111
Impaired loans with no related allowance, Interest Income Recognized	211		297
Impaired loans with a related allowance, Interest Income Recognized			133	1
Commercial Loans \| Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	1,844		1,844		284
Impaired loans with a related allowance, Recorded Investment	3,592		3,592		3,318
Impaired loans with no related allowance, Unpaid Principal balance	1,897		1,897		284
Impaired loans with a related allowance, Unpaid Principal Balance	8,732		8,732		8,502
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	3,293		3,293		3,192
Impaired loans with no related allowance, Average Recorded Investment	1,903	67	1,251	77
Impaired loans with a related allowance, Average Recorded Investment	3,592	3,922	3,350	3,973
Impaired loans with no related allowance, Interest Income Recognized		5	16	5
Impaired loans with a related allowance, Interest Income Recognized		72		72
Commercial Loans \| Multi-family Residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	20		20
Impaired loans with a related allowance, Recorded Investment					378
Impaired loans with no related allowance, Unpaid Principal balance	37		37
Impaired loans with a related allowance, Unpaid Principal Balance					397
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance					18
Impaired loans with no related allowance, Average Recorded Investment	37	879	36	1,196
Impaired loans with a related allowance, Average Recorded Investment			188
Impaired loans with no related allowance, Interest Income Recognized	1	4	5	4
Impaired loans with a related allowance, Interest Income Recognized			7
Commercial Loans \| Single-family Non-owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	1,016		1,016		383
Impaired loans with a related allowance, Recorded Investment	1,024		1,024		2,411
Impaired loans with no related allowance, Unpaid Principal balance	2,292		2,292		684
Impaired loans with a related allowance, Unpaid Principal Balance	1,097		1,097		2,460
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	179		179		996
Impaired loans with no related allowance, Average Recorded Investment	2,281	1,405	1,561	1,813
Impaired loans with a related allowance, Average Recorded Investment	1,098	2,888	1,413	2,910
Impaired loans with no related allowance, Interest Income Recognized	14	8	172	17
Impaired loans with a related allowance, Interest Income Recognized		11	6	42
Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	8,127		8,127		5,282
Impaired loans with a related allowance, Recorded Investment	1,863		1,863		2,781
Impaired loans with no related allowance, Unpaid Principal balance	9,062		9,062		5,362
Impaired loans with a related allowance, Unpaid Principal Balance	2,009		2,009		2,958
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	392		392		358
Impaired loans with no related allowance, Average Recorded Investment	9,068	886	7,512	1,119
Impaired loans with a related allowance, Average Recorded Investment	2,011	6,683	2,383	6,952
Impaired loans with no related allowance, Interest Income Recognized	84	7	508	17
Impaired loans with a related allowance, Interest Income Recognized		145	40	236
Commercial Loans \| Agricultural
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Related Allowance
Commercial Loans \| Farmland Loan
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	361		361
Impaired loans with no related allowance, Unpaid Principal balance	361		361
Impaired loans with no related allowance, Related Allowance
Impaired loans with no related allowance, Average Recorded Investment	361		225
Impaired loans with no related allowance, Interest Income Recognized			12
Consumer Real Estate \| Home Equity Lines
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	659		659		276
Impaired loans with a related allowance, Recorded Investment	217		217		223
Impaired loans with no related allowance, Unpaid Principal balance	687		687		277
Impaired loans with a related allowance, Unpaid Principal Balance	230		230		230
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	222		222		223
Impaired loans with no related allowance, Average Recorded Investment	708	378	503	503
Impaired loans with a related allowance, Average Recorded Investment	230	250	226	250
Impaired loans with no related allowance, Interest Income Recognized		8	49	14
Impaired loans with a related allowance, Interest Income Recognized			4
Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	2,213		2,213		277
Impaired loans with a related allowance, Recorded Investment	3,228		3,228		4,673
Impaired loans with no related allowance, Unpaid Principal balance	2,834		2,834		383
Impaired loans with a related allowance, Unpaid Principal Balance	3,374		3,374		4,903
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	593		593		806
Impaired loans with no related allowance, Average Recorded Investment	2,867	5,842	1,707	7,155
Impaired loans with a related allowance, Average Recorded Investment	3,377	2,581	3,931	2,697
Impaired loans with no related allowance, Interest Income Recognized		27	110	48
Impaired loans with a related allowance, Interest Income Recognized	4	28	26	53
Consumer Real Estate \| Owner occupied construction
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	50		50
Impaired loans with no related allowance, Unpaid Principal balance	61		61
Impaired loans with no related allowance, Related Allowance
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, Recorded Investment	8		8
Impaired loans with no related allowance, Unpaid Principal balance	12		12
Impaired loans with no related allowance, Related Allowance
Impaired loans with no related allowance, Average Recorded Investment	$ 12		$ 6

Impaired loans with no related investment, related allowance.

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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=28368275&loc=d3e5212-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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