Federal and State Income Taxes (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary cash dividends per common share for individual shareholder
Cash dividends per Common Share	$ 0.49	$ 0.69	$ 0.77
Ordinary Dividends [Member]
Summary cash dividends per common share for individual shareholder
Cash dividends per Common Share	$ 0.49	$ 0.69	$ 0.77
Capital Gains 15% Rate [Member]
Summary cash dividends per common share for individual shareholder
Cash dividends per Common Share
Nontaxable Distribution [Member]
Summary cash dividends per common share for individual shareholder
Cash dividends per Common Share