Loans - Summary of Credit Quality Indicate Financial Receivable (Loan Excluding Purchased Non-Covered and Covered Loans Portfolio) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	$ 1,695,382	$ 1,618,454	$ 1,492,753
Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	1,695,382	1,618,454	1,492,753
Excluding Purchased Non-Covered and Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	93,805	74,381	40,268
Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	243,963	230,212	232,773
Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	817,718	773,051	665,777
Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	31,056	31,604	29,403
Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	417,177	420,491	425,646
Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	38,240	30,591	32,485
Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	53,286	57,987	66,147
Excluding Purchased Non-Covered and Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	137	137	254
Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	270,571	244,373	180,888
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	270,571	244,373	180,888
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	86,688	66,983	32,223
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	26,730	24,789	11,569
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	90,692	93,852	75,503
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	120	127	45
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	55,827	50,373	52,631
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	5,386	2,111	3,324
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	5,001	6,011	5,494
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	127	127	99
Commercial, Financial and Agricultural [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	149,543	146,371	130,161
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	149,543	146,371	130,161
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	5,483	4,655	4,794
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	48,872	45,195	34,947
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	9,111	8,343	6,606
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	76,962	78,736	66,012
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	2,889	2,876	6,004
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	6,226	6,566	11,643
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade			155
Real Estate - Construction and Development [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	836,230	808,323	766,227
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	836,230	808,323	766,227
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	259	265	304
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	153,285	147,157	146,563
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	454,292	431,790	385,984
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	9,784	10,219	8,970
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	178,174	181,645	187,567
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	15,324	11,849	12,334
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	25,112	25,398	24,505
Real Estate - Commercial and Farmland [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	393,001	366,882	367,056
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	393,001	366,882	367,056
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	478	419	500
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	57,119	52,335	68,212
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	192,492	165,339	138,634
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	11,765	12,641	13,662
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	100,634	103,427	112,096
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	14,440	13,558	10,573
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	16,063	19,153	23,379
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	10	10
Real Estate - Residential [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	32,345	34,249	37,335
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	32,345	34,249	37,335
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	6,380	6,714	7,241
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	1,346	1,276	1,635
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	17,678	18,619	19,623
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	276	274	120
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	5,580	6,310	7,340
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	201	197	250
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	884	859	1,126
Consumer Installment Loans [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	13,692	18,256	11,086
Other [Member] | Excluding Purchased Non-Covered and Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	13,692	18,256	11,086
Other [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	13,692	18,256	11,086
Other [Member] | Excluding Purchased Non-Covered and Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade