Loans - Summary of Non-Covered Past Due Financial Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	$ 6,300		$ 27,400
Total Loans	1,695,382	1,618,454	1,492,753
Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	10,126	12,903
Loans 60-89 Days Past Due	7,614	3,314
Loans 90 or More Days Past Due	10,067	5,289
Total Loans Past Due	27,807	21,506
Current Loans	409,462	427,247
Total Loans	437,269	448,753
Loans 90 Days or More Past Due and Still Accruing
Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	270,571	244,373	180,888
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	291	370
Loans 60-89 Days Past Due		70
Loans 90 or More Days Past Due	117	11
Total Loans Past Due	408	451
Current Loans	30,402	31,690
Total Loans	30,810	32,141
Loans 90 Days or More Past Due and Still Accruing
Real Estate - Construction and Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	149,543	146,371	130,161
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	680	1,008
Loans 60-89 Days Past Due	661	89
Loans 90 or More Days Past Due	867	325
Total Loans Past Due	2,208	1,422
Current Loans	29,612	29,754
Total Loans	31,820	31,176
Loans 90 Days or More Past Due and Still Accruing
Real Estate - Commercial and Farmland [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	836,230	808,323	766,227
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	3,956	6,851
Loans 60-89 Days Past Due	5,126	2,064
Loans 90 or More Days Past Due	2,550	1,516
Total Loans Past Due	11,632	10,431
Current Loans	162,649	169,467
Total Loans	174,281	179,898
Loans 90 Days or More Past Due and Still Accruing
Real Estate - Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	393,001	366,882	367,056
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	5,187	4,667
Loans 60-89 Days Past Due	1,816	1,074
Loans 90 or More Days Past Due	6,503	3,428
Total Loans Past Due	13,506	9,169
Current Loans	182,572	191,682
Total Loans	196,078	200,851
Loans 90 Days or More Past Due and Still Accruing
Consumer Installment Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	32,345	34,249	37,335
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	12	7
Loans 60-89 Days Past Due	11	17
Loans 90 or More Days Past Due	30	9
Total Loans Past Due	53	33
Current Loans	4,227	4,654
Total Loans	4,280	4,687
Loans 90 Days or More Past Due and Still Accruing