Period-End Non-Accrual Loans, Segregated by Class (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	$ 14,855	$ 13,592
Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	12,644	11,248
Real Estate Loans | Land Development and Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	130	136
Real Estate Loans | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	281	352
Real Estate Loans | 1-4 Family Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	1,672	1,866
Real Estate Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	10,561	8,894
Business Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	2,131	2,224
Business Loans | Commercial and Industrial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	2,131	2,224
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	80	120
Consumer Loans | Other Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual Loans	$ 80	$ 120