Summary of Significant Accounting Policies (Schedule Of Performance Vesting Restricted Stock Units Granted) (Details)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Accounting Policies [Abstract]
Three-year performance period ending December 31,	2014		2013		2012
Vesting shares, target (in shares)	89,000	[1]	80,000	[1]	55,000	[1]
Vesting shares, maximum (in shares)	200,250	[1]	120,000	[1]	55,000	[1]
Restricted stock granted (in shares)					10,000

[1] 2010 grant includes 10,000 shares of restricted stock.