Earnings Per Share (Narrative) (Details)			3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2012 Class A Common Stock [Member]	Dec. 31, 2011 Class A Common Stock [Member]	Jun. 30, 2012 Class A Common Stock [Member] Stock Options [Member]	Jun. 30, 2011 Class A Common Stock [Member] Stock Options [Member]	Jun. 30, 2012 Class A Common Stock [Member] Stock Options [Member]	Jun. 30, 2011 Class A Common Stock [Member] Stock Options [Member]	Jun. 30, 2012 Class A Common Stock [Member] Restricted Stock [Member]	Jun. 30, 2012 Class A Common Stock [Member] Restricted Stock [Member]	Jun. 30, 2011 Class A Common Stock [Member] Restricted Stock [Member]	Jun. 30, 2012 Class B Common Stock [Member]	Dec. 31, 2011 Class B Common Stock [Member]
Common Stock, Shares Outstanding (Shares)	127,264,000	123,610,000								300,000,000	300,000,000
Anti-dilutive shares excluded from computation of earnings per share			400,000	900,000	400,000	1,200,000	2,700,000	1,500,000	400,000