Loans and Leases - Credit Quality Indicators (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	$ 1,541,484	$ 1,481,862
Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	8,459	2,263
Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	18,866	18,725
Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	54,169	68,702
Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	716,422	630,331
Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	219,350	267,560
Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	31,381	48,848
Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	101,941	87,550
Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	393	993
Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,150,981	1,124,972
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	388,558	355,202
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,945	1,688
Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	390,503	356,890
Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	422,816	468,421
Commercial, Financial and Agricultural [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	4,763	2,263
Commercial, Financial and Agricultural [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	6,051	5,227
Commercial, Financial and Agricultural [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	34,650	40,747
Commercial, Financial and Agricultural [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	251,203	260,042
Commercial, Financial and Agricultural [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	84,201	106,436
Commercial, Financial and Agricultural [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	10,095	31,825
Commercial, Financial and Agricultural [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	31,508	21,881
Commercial, Financial and Agricultural [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	345
Commercial, Financial and Agricultural [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Commercial, Financial and Agricultural [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	422,816	468,421
Real Estate-Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	600,353	530,122
Real Estate-Commercial Real Estate [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	2,014
Real Estate-Commercial Real Estate [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	8,515	9,591
Real Estate-Commercial Real Estate [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	17,758	25,837
Real Estate-Commercial Real Estate [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	384,061	321,194
Real Estate-Commercial Real Estate [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	113,181	110,476
Real Estate-Commercial Real Estate [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	19,445	16,187
Real Estate-Commercial Real Estate [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	55,331	45,844
Real Estate-Commercial Real Estate [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	48	993
Real Estate-Commercial Real Estate [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Commercial Real Estate [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	600,353	530,122
Real Estate-Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	90,493	91,250
Real Estate-Construction [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,682
Real Estate-Construction [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	4,300	3,907
Real Estate-Construction [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,500	1,783
Real Estate-Construction [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	54,464	26,331
Real Estate-Construction [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	16,084	42,190
Real Estate-Construction [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment		548
Real Estate-Construction [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	12,463	16,491
Real Estate-Construction [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Construction [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Construction [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	90,493	91,250
Real Estate-Residential Secured for Business Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	37,319	35,179
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 1. Cash secured/ 2. Fully secured [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 3. Strong [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 4. Satisfactory [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	261	335
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 5. Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	26,694	22,764
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 6. Pre-watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	5,884	8,458
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 7. Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,841	288
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 8. Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	2,639	3,334
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 9. Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Residential Secured for Business Purpose [Member] | Grade: 10. Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment
Real Estate-Residential Secured for Business Purpose [Member] | Internally Assigned Grades [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	37,319	35,179
Real Estate-Residential Secured for Personal Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	149,164	146,526
Real Estate-Residential Secured for Personal Purpose [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	148,063	145,722
Real Estate-Residential Secured for Personal Purpose [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	1,101	804
Real Estate-Residential Secured for Personal Purpose [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	149,164	146,526
Real Estate-Home Equity Secured for Personal Purpose [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	95,345	82,727
Real Estate-Home Equity Secured for Personal Purpose [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	95,245	82,673
Real Estate-Home Equity Secured for Personal Purpose [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	100	54
Real Estate-Home Equity Secured for Personal Purpose [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	95,345	82,727
Loans to Individuals [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	40,000	43,780
Loans to Individuals [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	39,645	43,395
Loans to Individuals [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	355	385
Loans to Individuals [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	40,000	43,780
Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	105,994	83,857
Lease Financing [Member] | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	105,605	83,412
Lease Financing [Member] | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	389	445
Lease Financing [Member] | Performing and Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases held for investment	$ 105,994	$ 83,857