Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Dec. 31, 2010
Class A Common Stock [Member]
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	350,000,000	350,000,000
Common Stock, shares outstanding	29,501,969	28,753,212
Treasury Stock, shares	59,400	59,400
Class B Common Stock [Member]
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	150,000,000	150,000,000
Common Stock, shares outstanding	25,984,625	26,317,960