Share-Based Compensation (Summary Of Information Of SERP) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Treasury shares issued to fund SERP expense	528,000
Deferred Compensation, Share-Based Payments [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of company match expensed under SERP	$ 444,000		$ 400,000		$ 315,000
Treasury shares issued to fund SERP expense	26,000		25,000		15,000
SERP trust account balance at December 31	18,942,000	[1]	16,534,000	[1]	14,591,000	[1]
Unrealized gain (loss) recorded in SERP liability account	$ (104,000)		$ 1,325,000		$ 1,797,000

[1] SERP trust account investments are recorded at their fair value which is based on quoted market prices. Differences between such amounts in the table above and the deferred compensation funding asset reported on our Consolidated Balance Sheets represent the value of our Common Stock held in the Plan's participants' trust account and reported by us as treasury stock in our Consolidated Balance Sheets.