v2.4.0.8
Summary of Cash, Cash Equivalents and Short-Term Investments (Parenthetical) (Detail) (USD $)
In Thousands, unless otherwise specified
9 Months Ended
Sep. 30, 2014
Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Unrealized loss $ 51 $ 2
Available for sale securities gross unrealized losses duration of loss Greater than 12 months  
Federal and municipal obligations
   
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Unrealized loss $ 18,900 $ 18,100