Summary Of Significant Accounting Policies (Schedule Of Anti-Dilutive Options To Purchase Common Shares, Excluded From Computation Of Earnings Per Share) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive options	$ 1,490,730	$ 1,873,070	$ 1,613,450
Minimum [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Options expiration date	Sep. 26, 2012
Maximum [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Options expiration date	May 18, 2021