Loans - Summary of Non-Covered Past Due Financial Receivables (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	$ 8,400		$ 20,700
Total Loans	1,770,059	1,618,454	1,555,827
Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	9,087	12,903
Loans 60-89 Days Past Due	2,811	3,314
Loans 90 or More Days Past Due	15,146	5,289
Total Loans Past Due	27,044	21,506
Current Loans	675,087	427,247
Total Loans	702,131	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	304,588	244,373	208,424
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	137	370
Loans 60-89 Days Past Due	26	70
Loans 90 or More Days Past Due	143	11
Total Loans Past Due	306	451
Current Loans	41,277	31,690
Total Loans	41,583	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	149,346	146,371	134,607
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	712	1,008
Loans 60-89 Days Past Due	168	89
Loans 90 or More Days Past Due	2,165	325
Total Loans Past Due	3,045	1,422
Current Loans	61,039	29,754
Total Loans	64,084	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	850,000	808,323	788,654
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	1,263	6,851
Loans 60-89 Days Past Due	1,605	2,064
Loans 90 or More Days Past Due	6,647	1,516
Total Loans Past Due	9,515	10,431
Current Loans	302,233	169,467
Total Loans	311,748	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	422,731	366,882	357,685
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	6,952	4,667
Loans 60-89 Days Past Due	983	1,074
Loans 90 or More Days Past Due	6,144	3,428
Total Loans Past Due	14,079	9,169
Current Loans	264,372	191,682
Total Loans	278,451	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	31,902	34,249	36,923
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30-59 Days Past Due	23	7
Loans 60-89 Days Past Due	29	17
Loans 90 or More Days Past Due	47	9
Total Loans Past Due	99	33
Current Loans	6,166	4,654
Total Loans	6,265	4,687
Loans 90 Days or More Past Due and Still Accruing