Loans - Summary of Risk Category of Loans By Class of Loans (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]    
Loans $ 889,150 $ 582,549
Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 131,657  
Real Estate - Mortgage [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 577,268 403,053
Real Estate - Construction [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 83,663 58,372
Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 13,962  
Leases [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   6
Receivables Factoring [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 82,600  
Adjustments [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 131,657 115,005
Adjustments [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 13,962 6,113
Pass [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 872,045 568,887
Pass [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 129,314  
Pass [Member] | Real Estate - Mortgage [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 565,992 392,568
Pass [Member] | Real Estate - Construction [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 82,552 58,372
Pass [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 13,192  
Pass [Member] | Leases [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   6
Pass [Member] | Receivables Factoring [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 80,995  
Pass [Member] | Adjustments [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   111,828
Pass [Member] | Adjustments [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   6,113
OAEM [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 5,511 5,086
OAEM [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 1,159  
OAEM [Member] | Real Estate - Mortgage [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 4,057 3,829
OAEM [Member] | Real Estate - Construction [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 94  
OAEM [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 201  
OAEM [Member] | Adjustments [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   1,257
Substandard [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 4,718 5,205
Substandard [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 1,184  
Substandard [Member] | Real Estate - Mortgage [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 2,803 3,312
Substandard [Member] | Real Estate - Construction [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 254  
Substandard [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 477  
Substandard [Member] | Adjustments [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   1,893
Doubtful [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 6,876 3,371
Doubtful [Member] | Real Estate - Mortgage [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 4,416 3,344
Doubtful [Member] | Real Estate - Construction [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 763  
Doubtful [Member] | Consumer [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 92  
Doubtful [Member] | Receivables Factoring [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans 1,605  
Doubtful [Member] | Adjustments [Member] | Commercial, Financial, and Agricultural [Member]    
Financing Receivable, Recorded Investment [Line Items]    
Loans   $ 27