Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Number of common shares issued	819,384
Series 2009 Preferred Stock [Member]
Preferred stock, dividends per share	$ 80	$ 80	$ 80
Series 2011 Preferred Stock [Member]
Preferred stock, dividends per share	$ 40	$ 40	$ 40