Loans - Summary of Credit Quality Indicate Financial Receivable (Non-Covered Loan Portfolio) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	$ 1,770,059	$ 1,618,454	$ 1,555,827
Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	702,131	448,753
Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	4,344	2,605
Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	35,540	34,474
Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	186,690	88,893
Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	165
Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	416,671	274,442
Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	32,309	22,962
Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	26,412	25,377
Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	304,588	244,373	208,424
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	41,583	32,141
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	3,494	1,865
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	4,728	4,606
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	11,567	5,172
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	18,251	19,638
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	3,162	576
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	381	284
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Commercial, Financial and Agricultural [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	149,346	146,371	134,607
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	64,084	31,176
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	245	7
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	12,905	3,960
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	42,127	20,733
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	4,722	1,760
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	4,085	4,716
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Construction and Development [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	850,000	808,323	788,654
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	311,748	179,898
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	14,191	12,998
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	94,598	43,802
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	175,427	102,260
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	16,078	9,554
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	11,454	11,284
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Commercial and Farmland [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	422,731	366,882	357,685
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	278,451	200,851
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	293	289
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	15,839	16,160
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	64,937	34,576
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	165
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	178,523	129,923
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	8,326	10,878
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	10,368	9,025
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Real Estate - Residential [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	31,902	34,249	36,923
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	6,265	4,687
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	557	451
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	537	703
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	2,683	1,383
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	2,343	1,888
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	21	194
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	124	68
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Consumer Installment Loans [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade	11,492	18,256	29,534
Other [Member] | Purchased Non-Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 10 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 15 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 20 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 23 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 25 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 30 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 40 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 50 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade
Other [Member] | Purchased Non-Covered Loans [Member] | 60 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans portfolio by risk grade