Junior Subordinated Debentures (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 item
Debt Instrument [Line Items]
Number of issuances of junior subordinated debentures	2
DNB Capital Trust I [Member]
Debt Instrument [Line Items]
Issuance date	Jul. 20, 2001
Floating rate capital preferred securities	$ 5.0
LIBOR rate, borrowing period, in months	6 months
Basis spread on variable rate	3.75%
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
LIBOR rate, borrowing period, in months	3 months
Basis spread on variable rate	1.77%
Fixed interest rate	6.56%
Interest rate period, in years	5 years
Principal amount, floating rate junior subordinated debentures	$ 4.1
Maturity date range, start	May 23, 2010
Maturity date range, end	May 23, 2035