Aging of Past Due Loans by Loan Class (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	$ 8,544	$ 12,307
60 - 89 Days Past Due	4,100	2,802
90+ Days Past Due	11,763	11,961
Total Past Due	24,407	27,070
Current Loans	1,707,457	1,683,651
Total loans	1,731,864	1,710,721
Non Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	7,670	10,929
60 - 89 Days Past Due	3,677	2,552
90+ Days Past Due	10,802	9,112
Total Past Due	22,149	22,593
Current Loans	1,566,545	1,536,446
Total loans	1,588,694	1,559,039
Non Covered Loans | Commercial Loans | Construction Development And Other Land
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	111	118
60 - 89 Days Past Due	113	10
90+ Days Past Due	217	532
Total Past Due	441	660
Current Loans	45,220	34,595
Total loans	45,661	35,255
Non Covered Loans | Commercial Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	59	93
60 - 89 Days Past Due		39
90+ Days Past Due	2,576	2,631
Total Past Due	2,635	2,763
Current Loans	91,768	92,692
Total loans	94,403	95,455
Non Covered Loans | Commercial Loans | Multi-family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	85	115
90+ Days Past Due	115
Total Past Due	200	115
Current Loans	75,394	70,082
Total loans	75,594	70,197
Non Covered Loans | Commercial Loans | Single-family Non-owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	432	611
60 - 89 Days Past Due	254	554
90+ Days Past Due	1,527	1,203
Total Past Due	2,213	2,368
Current Loans	135,756	133,191
Total loans	137,969	135,559
Non Covered Loans | Commercial Loans | Non-farm, Non-residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	1,216	1,014
60 - 89 Days Past Due	203	318
90+ Days Past Due	2,325	1,770
Total Past Due	3,744	3,102
Current Loans	480,617	472,809
Total loans	484,361	475,911
Non Covered Loans | Commercial Loans | Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	8
Total Past Due	8
Current Loans	2,085	2,324
Total loans	2,093	2,324
Non Covered Loans | Commercial Loans | Farmland Loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due		245
90+ Days Past Due	432
Total Past Due	432	245
Current Loans	31,978	32,369
Total loans	32,410	32,614
Non Covered Loans | Consumer Real Estate | Home Equity Lines
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	479	289
60 - 89 Days Past Due	80	317
90+ Days Past Due	191	442
Total Past Due	750	1,048
Current Loans	112,387	110,722
Total loans	113,137	111,770
Non Covered Loans | Consumer Real Estate | Single Family Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	4,771	7,428
60 - 89 Days Past Due	2,951	1,228
90+ Days Past Due	3,390	145
Total Past Due	11,112	8,801
Current Loans	481,515	487,211
Total loans	492,627	496,012
Non Covered Loans | Consumer Real Estate | Owner occupied construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due		205
90+ Days Past Due		2,284
Total Past Due		2,489
Current Loans	34,360	26,214
Total loans	34,360	28,703
Non Covered Loans | Consumer and Other | Consumer Loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	509	811
60 - 89 Days Past Due	76	86
90+ Days Past Due	29	105
Total Past Due	614	1,002
Current Loans	71,497	70,311
Total loans	72,111	71,313
Non Covered Loans | Consumer and Other | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	3,968	3,926
Total loans	3,968	3,926
Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	874	1,378
60 - 89 Days Past Due	423	250
90+ Days Past Due	961	2,849
Total Past Due	2,258	4,477
Current Loans	140,912	147,205
Total loans	143,170	151,682
Covered Loans | Commercial Loans | Construction Development And Other Land
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	178	479
60 - 89 Days Past Due	10
90+ Days Past Due	74	453
Total Past Due	262	932
Current Loans	15,694	14,933
Total loans	15,956	15,865
Covered Loans | Commercial Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due		5
60 - 89 Days Past Due		44
90+ Days Past Due	35	92
Total Past Due	35	141
Current Loans	3,027	3,184
Total loans	3,062	3,325
Covered Loans | Commercial Loans | Multi-family Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,903	1,933
Total loans	1,903	1,933
Covered Loans | Commercial Loans | Single-family Non-owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
90+ Days Past Due	114	184
Total Past Due	114	184
Current Loans	6,680	7,265
Total loans	6,794	7,449
Covered Loans | Commercial Loans | Non-farm, Non-residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	195	209
60 - 89 Days Past Due	354
Total Past Due	549	209
Current Loans	30,909	34,437
Total loans	31,458	34,646
Covered Loans | Commercial Loans | Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	162	164
Total loans	162	164
Covered Loans | Commercial Loans | Farmland Loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
90+ Days Past Due		301
Total Past Due		301
Current Loans	817	572
Total loans	817	873
Covered Loans | Consumer Real Estate | Home Equity Lines
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	353	488
60 - 89 Days Past Due	1	86
90+ Days Past Due	187	163
Total Past Due	541	737
Current Loans	66,354	68,469
Total loans	66,895	69,206
Covered Loans | Consumer Real Estate | Single Family Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	148	197
60 - 89 Days Past Due	58	120
90+ Days Past Due	434	1,466
Total Past Due	640	1,783
Current Loans	14,647	15,136
Total loans	15,287	16,919
Covered Loans | Consumer Real Estate | Owner occupied construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
90+ Days Past Due	117	190
Total Past Due	117	190
Current Loans	610	994
Total loans	727	1,184
Covered Loans | Consumer and Other | Consumer Loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	109	118
Total loans	$ 109	$ 118