Stockholders' Equity (Schedule Of Outstanding Preferred Stock) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Stockholders' Equity [Line Items]
Convertible, number of equity instruments	1,733
$1.60 Cumulative Preferred Stock, Series A [Member]
Stockholders' Equity [Line Items]
Annual Dividend	$ 1.60		$ 1.60
Conversion Rate	1.6562	[1]
Recorded Amount	$ 13.98
Liquidation Preference	$ 16.40
Redemption Price	$ 16.40
Convertible, number of equity instruments	1,050
$1.26 Cumulative Convertible Preferred Stock, Series B [Member]
Stockholders' Equity [Line Items]
Annual Dividend	$ 1.26		$ 1.26
Conversion Rate	0.6399	[1]
Recorded Amount	$ 11.24
Liquidation Preference	$ 11.38
Redemption Price	$ 12.50

[1] Reflects the number of common shares to be received for each preferred share converted based on conversion rates in effect January 1, 2012 for the Series A shares and December 31, 2011 for the Series B shares. During 2011, 1,050 Series A shares were converted into 1,733 common shares.