Subordinated Debentures (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2008	Nov. 15, 2008
Debt Instrument [Line Items]
Number of private placement offering			70
Private placement offering price (per unit)			$ 100,000
Gross proceeds of private placement		$ 7,000,000
Number of shares consisted in each unit (in shares)		6,250
Annual interest rate on subordinated notes (in hundredths)			8.00%
Subordinated Note, original principal amount			50,000
Preferred stock dividend rate percentage (in hundredths)		8.00%
Debt issuance costs		245,000
Finance cost amortization period		10 years
Interest on unpaid interest	381,000
Junior Subordinated Debt Securities [Member]
Debt Instrument [Line Items]
Junior subordinated debt securities principal amount	20,619,000
Floating rate of interest	3-month LIBOR (0.34% December 31, 2012)
Basis points (in hundredths)	2.00%
Maturity date	Jan. 07, 2035
Proceeds from issuance of debentures	$ 17,000,000
Severn Capital Trust I [Member]
Debt Instrument [Line Items]
Common equity owned (in hundredths)	100.00%