Loans - Summary of Covered Past Due Financial Receivables (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 30-59 Days Past Due	$ 6,300		$ 27,400
Total Loans	1,695,382	1,618,454	1,492,753
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	24,249	20,990	20,603
Loans 60-89 Days Past Due	5,714	6,434	4,383
Loans 90 or More Days Past Due	50,983	57,197	86,249
Total Loans Past Due	80,946	84,621	111,235
Current Loans	291,748	305,616	349,489
Total Loans	372,694	390,237	460,724
Loans 90 Days or More Past Due and Still Accruing	1,396	346	146
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	270,571	244,373	180,888
Commercial, Financial and Agricultural [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	688	3,966	756
Loans 60-89 Days Past Due	55	12	314
Loans 90 or More Days Past Due	8,976	6,165	7,270
Total Loans Past Due	9,719	10,143	8,340
Current Loans	15,094	16,407	20,228
Total Loans	24,813	26,550	28,568
Loans 90 Days or More Past Due and Still Accruing			98
Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	149,543	146,371	130,161
Real Estate - Construction and Development [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	4,248	843	3,971
Loans 60-89 Days Past Due	302	144	876
Loans 90 or More Days Past Due	14,472	14,055	17,415
Total Loans Past Due	19,022	15,042	22,262
Current Loans	22,412	28,137	34,852
Total Loans	41,434	43,179	57,114
Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	836,230	808,323	766,227
Real Estate - Commercial and Farmland [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	15,732	8,482	10,227
Loans 60-89 Days Past Due	3,722	4,350	2,837
Loans 90 or More Days Past Due	17,680	26,428	42,464
Total Loans Past Due	37,134	39,260	55,528
Current Loans	177,515	185,191	204,631
Total Loans	214,649	224,451	260,159
Loans 90 Days or More Past Due and Still Accruing		346
Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	393,001	366,882	367,056
Real Estate - Residential [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	3,579	7,648	5,608
Loans 60-89 Days Past Due	1,585	1,914	345
Loans 90 or More Days Past Due	9,752	10,244	18,895
Total Loans Past Due	14,916	19,806	24,848
Current Loans	76,456	75,367	88,820
Total Loans	91,372	95,173	113,668
Loans 90 Days or More Past Due and Still Accruing	1,396		48
Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	32,345	34,249	37,335
Consumer Installment Loans [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans 30-59 Days Past Due	2	51	41
Loans 60-89 Days Past Due	50	14	11
Loans 90 or More Days Past Due	103	305	205
Total Loans Past Due	155	370	257
Current Loans	271	514	958
Total Loans	$ 426	$ 884	$ 1,215