Stockholders' Equity (Share Count And Par Value Data Related To Stockholders' Equity) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders' Equity [Abstract]
Preferred Stock, Par value per share	$ 0.01	$ 0.01
Preferred Stock, Shares authorized	10,000,000	10,000,000
Preferred Stock, Shares outstanding	0	0
Common Stock - Class A, Par value per share	$ 0.01	$ 0.01
Common Stock - Class A, Shares authorized	150,000,000	150,000,000
Common Stock - Class A, Shares issued	72,151,857	72,151,857
Common Stock - Class A, Shares outstanding	52,095,166	55,711,325	58,318,983
Treasury Stock, Shares held	20,056,691	16,440,532