v2.4.0.6
Geographic Information (Composition of Company's Property and Equipment) (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Dec. 31, 2011
Schedule Of Geographical Information [Line Items]          
Total Revenues $ 64,273 $ 58,759 $ 186,839 $ 169,805  
Total 30,427   30,427   28,272
UNITED STATES
         
Schedule Of Geographical Information [Line Items]          
Total Revenues 46,979 42,954 135,507 126,861  
Total 23,557   23,557   22,834
Europe [Member]
         
Schedule Of Geographical Information [Line Items]          
Total Revenues 10,361 9,727 31,273 25,169  
Total 5,728   5,728   4,526
CANADA
         
Schedule Of Geographical Information [Line Items]          
Total Revenues 2,922 2,607 8,429 7,221  
Total 311   311   344
Other [Member]
         
Schedule Of Geographical Information [Line Items]          
Total Revenues 4,011 3,471 11,630 10,554  
Total $ 831   $ 831   $ 568