Loans - Summary of Impaired Financial Receivables (Analysis of Covered Impaired Loans) (Detail) (Covered Loans [Member], USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	$ 64,456		$ 91,407
Recorded Investment With No Allowance	55,359	99,192	77,561
Recorded Investment With Allowance
Total Recorded Investment	55,359	99,192	77,561
Related Allowance
Average Recorded Investment	70,932	104,473	94,873
Covered Loans [Member] | Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	14,617		9,598
Recorded Investment With No Allowance	12,254		7,257
Recorded Investment With Allowance
Total Recorded Investment	12,254		7,257
Related Allowance
Average Recorded Investment	10,525		8,676
Covered Loans [Member] | Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	9,780		17,540
Recorded Investment With No Allowance	8,028		14,781
Recorded Investment With Allowance
Total Recorded Investment	8,028		14,781
Related Allowance
Average Recorded Investment	13,380		17,909
Covered Loans [Member] | Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	21,236		39,056
Recorded Investment With No Allowance	18,093		34,074
Recorded Investment With Allowance
Total Recorded Investment	18,093		34,074
Related Allowance
Average Recorded Investment	27,174		44,652
Covered Loans [Member] | Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	18,662		24,819
Recorded Investment With No Allowance	16,857		21,108
Recorded Investment With Allowance
Total Recorded Investment	16,857		21,108
Related Allowance
Average Recorded Investment	19,641		23,332
Covered Loans [Member] | Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	161		394
Recorded Investment With No Allowance	127		341
Recorded Investment With Allowance
Total Recorded Investment	127		341
Related Allowance
Average Recorded Investment	212		304
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		122,867
Recorded Investment With No Allowance		99,192
Recorded Investment With Allowance
Total Recorded Investment		99,192
Related Allowance
Average Recorded Investment		104,473
Covered Loans [Member] | Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		12,151
Recorded Investment With No Allowance		8,769
Recorded Investment With Allowance
Total Recorded Investment		8,769
Related Allowance
Average Recorded Investment		9,417
Covered Loans [Member] | Real Estate - Construction and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		24,044
Recorded Investment With No Allowance		19,198
Recorded Investment With Allowance
Total Recorded Investment		19,198
Related Allowance
Average Recorded Investment		19,394
Covered Loans [Member] | Real Estate - Commercial and Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		58,538
Recorded Investment With No Allowance		48,000
Recorded Investment With Allowance
Total Recorded Investment		48,000
Related Allowance
Average Recorded Investment		50,508
Covered Loans [Member] | Real Estate - Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		27,794
Recorded Investment With No Allowance		22,940
Recorded Investment With Allowance
Total Recorded Investment		22,940
Related Allowance
Average Recorded Investment		24,877
Covered Loans [Member] | Consumer Installment Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance		340
Recorded Investment With No Allowance		285
Recorded Investment With Allowance
Total Recorded Investment		285
Related Allowance
Average Recorded Investment		$ 277