Consolidated Statements of Stockholders' Equity (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Preferred Stock [Member]
Dividends declared to preferred stockholders per share	$ 0.80	$ 0.80	$ 0.80
Common Stock [Member]
Dividends declared to common stockholders per share	$ 2.20	$ 1.18	$ 1.10