Quarterly report pursuant to Section 13 or 15(d)

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical)

v2.4.0.6
Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)
Sep. 30, 2012
Dec. 31, 2011
Convertible preferred stock issued      
Treasury stock, shares 16,687,779 15,777,747
Common Class A
   
Common stock, par value 0.01 0.01
Common stock, shares authorized 100,000,000 100,000,000
Common stock, shares issued 61,191,866 56,377,778
Common stock, shares outstanding 44,504,087 40,600,031
Common Class B
   
Common stock, par value 0.01 0.01
Common stock, shares authorized 30,000,000 30,000,000
Common stock, shares issued 12,029,375 12,029,375
Common stock, shares outstanding 12,029,375 12,029,375