Quarterly report pursuant to Section 13 or 15(d)

Per Share Data and Stockholders' Equity (Details Textual)

v2.4.0.6
Per Share Data and Stockholders' Equity (Details Textual)
In Millions, unless otherwise specified
9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Per Share Data and Stockholders' Equity (Textual) [Abstract]    
Interest rate on Convertible note 5.00%  
5.0% Convertible Senior Notes [Member]
   
Per Share Data and Stockholders' Equity (Textual) [Abstract]    
Interest rate on Convertible note 5.00%  
Common Class A [Member]
   
Per Share Data and Stockholders' Equity (Textual) [Abstract]    
Antidilutive stock options included in computation of diluted earnings per share 1.3 2.1