Loans and Leases - Concessions Granted on Accruing and Nonaccrual Loans Restructured (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended				3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2013 Accruing Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2013 Accruing Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2013 Accruing Troubled Debt Restructured Loans [Member] Interest Only Term Extension [Member] Loans	Jun. 30, 2013 Accruing Troubled Debt Restructured Loans [Member] Interest Only Term Extension [Member] Loans	Jun. 30, 2014 Nonaccrual Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2014 Nonaccrual Troubled Debt Restructured Loans [Member] Interest Rate Reduction [Member] Loans	Jun. 30, 2014 Nonaccrual Troubled Debt Restructured Loans [Member] Maturity Date Extension [Member] Loans	Jun. 30, 2013 Commercial, Financial and Agricultural [Member] Accruing Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2013 Commercial, Financial and Agricultural [Member] Accruing Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2013 Commercial, Financial and Agricultural [Member] Accruing Troubled Debt Restructured Loans [Member] Interest Only Term Extension [Member] Loans	Jun. 30, 2013 Commercial, Financial and Agricultural [Member] Accruing Troubled Debt Restructured Loans [Member] Interest Only Term Extension [Member] Loans	Jun. 30, 2014 Real Estate-Commercial [Member] Nonaccrual Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2014 Real Estate-Commercial [Member] Nonaccrual Troubled Debt Restructured Loans [Member] Interest Rate Reduction [Member] Loans	Jun. 30, 2014 Real Estate-Residential Secured for Business Purpose [Member] Nonaccrual Troubled Debt Restructured Loans [Member] Loans	Jun. 30, 2014 Real Estate-Residential Secured for Business Purpose [Member] Nonaccrual Troubled Debt Restructured Loans [Member] Interest Rate Reduction [Member] Loans	Jun. 30, 2014 Real Estate-Residential Secured for Business Purpose [Member] Nonaccrual Troubled Debt Restructured Loans [Member] Maturity Date Extension [Member] Loans
Concessions granted on accruing and non-accrual loans restructured
No. of Loans	1	1	1	1	3	2	1	1	1	1	1	1	1	2	1	1
Amount	$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 738	$ 105	$ 633	$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 50	$ 50	$ 688	$ 55	$ 633