Allowance for Loan Losses - Non Accrual Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	$ 14,860	$ 19,594
Construction [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	10	14
Land, Farmland, Agriculture [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	607	709
Residential / Prime [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	6,215	7,152
Residential / Subprime [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	6,519	9,195
Commercial and Non-Residential [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	1,080	1,967
Consumer [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	395	491
Commercial and Industrial [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	34	66
Multi Family [Member]
Financing Receivable Recorded Investment Nonaccrual Status [Abstract]
Non-accrual loans	$ 0	$ 0