Junior Subordinated Debentures (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
DNB Capital Trust I [Member]
Debt Instrument [Line Items]
Issuance date	Jul. 20, 2001
Floating rate capital preferred securities	$ 5.0
Description of variable rate basis	floating rate (6 month Libor plus 3.75%, with a cap of 12%)
Maximum stated interest rate range	12.00%
Principal amount, floating rate junior subordinated debentures	5.2
Maturity date range, start	Jul. 25, 2006
Maturity date range, end	Jul. 25, 2031
DNB Capital Trust II [Member]
Debt Instrument [Line Items]
Issuance date	Mar. 30, 2005
Floating rate capital preferred securities	4.0
Description of variable rate basis	floating rate (the rate was fixed at 6.56% for the first 5 years and is now adjusting at a rate of 3-month LIBOR plus 1.77%)
Principal amount, floating rate junior subordinated debentures	$ 4.1
Maturity date range, start	May 23, 2010
Maturity date range, end	May 23, 2035