Earnings Per Share (Schedule of Shares Issued and Outstanding) (Details)	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011
Class of Stock [Line Items]
Less: Treasury Shares	(8,467,873)	(8,479,487)	(8,479,487)	(8,479,487)
Net shares Outstanding	31,357,529	31,341,615	31,297,453	31,272,553
Class A Common Stock [Member]
Class of Stock [Line Items]
Common Stock, shares issued	36,589,304	36,585,004	36,540,842	36,515,942
Class B Common Stock [Member]
Class of Stock [Line Items]
Common Stock, shares issued	3,236,098	3,236,098	3,236,098	3,236,098
Net shares Outstanding	3,236,098		3,236,098