Share-Based Compensation (Summary Of Information Of SERP) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Treasury shares issued to fund SERP expense	541
Deferred Compensation, Share-Based Payments [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of company match expensed under SERP	$ 560		$ 444		$ 400
Treasury shares issued to fund SERP expense	24		26		25
SERP trust account balance at December 31	24,997	[1]	18,942	[1]	16,534	[1]
Unrealized gain (loss) recorded in SERP liability account	$ 1,718		$ (104)		$ 1,325

[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.