Balance Sheet Details - Changes in Deferred Services Revenue (Details) (Software Service, Support and Maintenance Arrangement, USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Software Service, Support and Maintenance Arrangement
   
Deferred Revenue Arrangement [Line Items]    
Balance at beginning of period $ 257,280 $ 253,793
Additions to deferred service revenue 87,848 85,894
Amortization of deferred service revenue (86,186) (86,643)
Balance at end of period $ 258,942 $ 253,044