Consolidated Statements Of Shareholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2012 Preferred Stock Series 2009 [Member]	Mar. 31, 2012 Preferred Stock Series 2011 [Member]
Preferred stock, dividend per share		$ 20.00	$ 20.00
Preferred stock cash dividends declared per share	$ 20.00