Other Equity Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Other Securities Owned [Line Items]
Federal Reserve Bank stock	$ 8,269	$ 7,530
Federal Home Loan Bank of Atlanta stock	25,367	27,328
Other equities	33,636	34,933
Atlantic Central Bankers Bank Stock
Other Securities Owned [Line Items]
Other equities	$ 0	$ 75