Stockholders' Equity (Details) (USD $)	0 Months Ended	3 Months Ended					6 Months Ended	12 Months Ended
	Sep. 21, 2011	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Jun. 30, 2013	Dec. 31, 2010
Class of Stock [Line Items]
Liquidation preference per share		$ 1,000		$ 1,000			$ 1,000
Aggregate purchase price		$ 11,750,000					$ 11,750,000
Securities purchase agreement, share repurchase amount							11,879,000
Securities purchase agreement, share repurchase paid in principal amount							11,750,000
Securities purchase agreement, share repurchase accrued unpaid dividends amount							128,900
Number of stock repurchase from treasury		186,311					186,311
Repurchase of stock warrants	458,000
Shares of common stock		186,311					186,311
Par value per share		$ 1.00		$ 1.00			$ 1.00
Exercise price per share		$ 9.46					$ 9.46
Treasury's small business lending fund								30,000,000,000
Treasury's small business lending fund, maximum asset value, qualified banks								10,000,000,000
Preferred stock dividend rate		1.00%	1.00%	1.00%	1.00%	3.90%	3.874%
Expected dividend rate at a fixed rate for a specified period							9.00%
Par value per share		$ 10.00		$ 10.00			$ 10.00
Cumulative Preferred Stock [Member]
Class of Stock [Line Items]
Shares of perpetual preferred stock		11,750					11,750
Liquidation preference per share		$ 1,000					$ 1,000
Par value per share		$ 10.00					$ 10.00
Noncumulative Preferred Stock [Member]
Class of Stock [Line Items]
Shares of perpetual preferred stock		13,000					13,000
Liquidation preference per share		$ 1,000					$ 1,000
Aggregate purchase price		$ 13,000,000					$ 13,000,000
Minimum [Member]
Class of Stock [Line Items]
Expected dividend rate for the second through tenth dividend periods							1.00%
Expected dividend rate at a fixed rate for a specified period							1.00%
Maximum [Member]
Class of Stock [Line Items]
Expected dividend rate for the second through tenth dividend periods							5.00%
Expected dividend rate at a fixed rate for a specified period							7.00%