Recorded Investment In Loans Considered To Be Impaired And Related Information On Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	$ 15,574		$ 15,574		$ 9,418
Impaired loans with a related allowance, Recorded Investment	11,570		11,570		13,784
Total impaired loans, Recorded Investment	27,144		27,144		23,202
Impaired loans with no related allowance, Unpaid Principal balance	18,850		18,850		9,906
Impaired loans with a related allowance, Unpaid Principal Balance	17,141		17,141		19,450
Total impaired loans, Unpaid Principal Balance	35,991		35,991		29,356
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	5,256		5,256		5,593
Total impaired loans, Related Allowance	5,256		5,256		5,593
Impaired loans with no related allowance, Average Recorded Investment	18,893	9,511	17,859	13,251
Impaired loans with a related allowance, Average Recorded Investment	12,390	16,220	13,046	16,729
Total impaired loans, Average Recorded Investment	31,283	25,731	30,905	29,980
Impaired loans with no related allowance, Interest Income Recognized	43	86	1,658	244
Impaired loans with a related allowance, Interest Income Recognized	33	105	287	578
Total impaired loans, Interest Income Recognized	76	191	1,945	822
Commercial Loans \| Construction Development And Other Land
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	4,229		4,229		2,916
Impaired loans with a related allowance, Recorded Investment	459		459
Impaired loans with no related allowance, Unpaid Principal balance	6,376		6,376		2,916
Impaired loans with a related allowance, Unpaid Principal Balance	459		459
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	347		347
Impaired loans with no related allowance, Average Recorded Investment	6,375	784	5,133	1,296
Impaired loans with a related allowance, Average Recorded Investment	463	55	1,409	55
Impaired loans with no related allowance, Interest Income Recognized	40		591
Impaired loans with a related allowance, Interest Income Recognized			141	1
Commercial Loans \| Commercial and Industrial
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment					284
Impaired loans with a related allowance, Recorded Investment	4,743		4,743		3,318
Impaired loans with no related allowance, Unpaid Principal balance					284
Impaired loans with a related allowance, Unpaid Principal Balance	10,084		10,084		8,502
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	3,648		3,648		3,192
Impaired loans with no related allowance, Average Recorded Investment		449	834	559
Impaired loans with a related allowance, Average Recorded Investment	5,328	3,600	4,009	3,662
Impaired loans with no related allowance, Interest Income Recognized		3	16	13
Impaired loans with a related allowance, Interest Income Recognized	11		11	163
Commercial Loans \| Multi-family Residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with a related allowance, Recorded Investment					378
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		591	24	1,146
Impaired loans with a related allowance, Average Recorded Investment		193	126	1,309
Impaired loans with no related allowance, Interest Income Recognized			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	289		289		383
Impaired loans with a related allowance, Recorded Investment	313		313		2,411
Impaired loans with no related allowance, Unpaid Principal balance	317		317		684
Impaired loans with a related allowance, Unpaid Principal Balance	365		365		2,460
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	38		38		996
Impaired loans with no related allowance, Average Recorded Investment	317	954	1,146	524
Impaired loans with a related allowance, Average Recorded Investment	365	2,066	1,064	619
Impaired loans with no related allowance, Interest Income Recognized		4	182	29
Impaired loans with a related allowance, Interest Income Recognized			8	57
Commercial Loans \| Non-farm, Non-residential
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	7,408		7,408		5,282
Impaired loans with a related allowance, Recorded Investment	606		606		2,781
Impaired loans with no related allowance, Unpaid Principal balance	8,192		8,192		5,362
Impaired loans with a related allowance, Unpaid Principal Balance	606		606		2,958
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	7		7		358
Impaired loans with no related allowance, Average Recorded Investment	8,194	1,584	7,739	2,872
Impaired loans with a related allowance, Average Recorded Investment	606	6,454	1,791	5,802
Impaired loans with no related allowance, Interest Income Recognized		41	630	65
Impaired loans with a related allowance, Interest Income Recognized		90	52	291
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	659		659
Impaired loans with no related allowance, Unpaid Principal balance	668		668
Impaired loans with no related allowance, Related Allowance
Impaired loans with no related allowance, Average Recorded Investment	667	372	372	508
Impaired loans with a related allowance, Average Recorded Investment		372		372
Impaired loans with no related allowance, Interest Income Recognized	3		18
Consumer Real Estate \| Home Equity Lines
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	541		541		276
Impaired loans with a related allowance, Recorded Investment	519		519		223
Impaired loans with no related allowance, Unpaid Principal balance	546		546		277
Impaired loans with a related allowance, Unpaid Principal Balance	535		535		230
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	434		434		223
Impaired loans with no related allowance, Average Recorded Investment	546	321	518	592
Impaired loans with a related allowance, Average Recorded Investment	535	125	329	83
Impaired loans with no related allowance, Interest Income Recognized			66	20
Impaired loans with a related allowance, Interest Income Recognized	9		14
Consumer Real Estate \| Single Family Owner Occupied
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Recorded Investment	2,448		2,448		277
Impaired loans with a related allowance, Recorded Investment	4,930		4,930		4,673
Impaired loans with no related allowance, Unpaid Principal balance	2,751		2,751		383
Impaired loans with a related allowance, Unpaid Principal Balance	5,092		5,092		4,903
Impaired loans with no related allowance, Related Allowance
Impaired loans with a related allowance, Related Allowance	782		782		806
Impaired loans with no related allowance, Average Recorded Investment	2,794	4,456	2,069	5,727
Impaired loans with a related allowance, Average Recorded Investment	5,093	3,355	4,318	4,827
Impaired loans with no related allowance, Interest Income Recognized		38	145	113
Impaired loans with a related allowance, Interest Income Recognized	13	15	54	66
Consumer Real Estate \| Owner occupied construction
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Related Allowance
Impaired loans with no related allowance, Average Recorded Investment			20	1
Impaired loans with no related allowance, Interest Income Recognized			5
Consumer and Other \| Consumer Loan
Financing Receivable, Recorded Investment [Line Items]
Impaired loans with no related allowance, Related Allowance
Impaired loans with no related allowance, Average Recorded Investment			$ 4	$ 26

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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-Publisher FASB

-Name Accounting Standards Codification

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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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