Loans and Leases - Accruing and nonaccrual troubled debt restructured loans with payment default (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013 Loans	Jun. 30, 2012 Loans	Jun. 30, 2013 Loans	Jun. 30, 2012 Loans
Accruing Troubled Debt Restructured Loans [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans			3
Recorded investment			$ 230
Nonaccrual Troubled Debt Restructured Loans [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans
Recorded investment
Commercial, financial and agricultural [Member] | Accruing Troubled Debt Restructured Loans [Member]
Accruing and nonaccrual troubled debt restructured loans with payment default
Number of Loans			3
Recorded investment			$ 230