CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Balance Sheet Parentheticals [Line Items]
Preferred stock par value	$ 0.01	$ 0.01
Preferred stock shares authorized	5,000,000	5,000,000
Preferred stock shares issued	0	0
Common stock in treasury, shares	13,059,002	12,897,610
Class A
Balance Sheet Parentheticals [Line Items]
Common Stock Shares Issued and Outstanding	74,272,334	71,863,191
Common Stock Par Value	$ 0.014	$ 0.014
Common Stock Shares Authorized	150,000,000	150,000,000
Class B
Balance Sheet Parentheticals [Line Items]
Common Stock Shares Issued and Outstanding	0	0
Common Stock Par Value	$ 0.014	$ 0.014
Common Stock Shares Authorized	1,000,000	1,000,000