v2.4.0.6
Commitments And Contingencies (Narrative) (Details) (USD $)
In Millions, except Share data, unless otherwise specified
0 Months Ended 12 Months Ended 3 Months Ended
Dec. 20, 2011
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2011
Patents [Member]
Commitments And Contingencies [Line Items]          
Total rent expense, under non-cancellable operating leases   $ 6.7 $ 5.6 $ 4.9  
Deferred rent and capitalized assets   0.3 0.4    
Number of shares issued under patent purchase 974,358        
Restricted common stock   16.2      
Amount allocated to acquired patents   11.0     26.0
Amount allocated to litigation settlement   $ 5.2     $ 12.2
Percentage of acquired patents   50.00%      
Date of patents amortized   July 2018      
Percentage of acquired patents in different period   50.00%      
Date of patents amortized in different period   September 2024