XML 71 R42.htm IDEA: XBRL DOCUMENT v3.10.0.1
Marketable Securities and Fair Value Measurements - Fair Value Measured On A Recurring Basis (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Apr. 30, 2018
Dec. 31, 2017
Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments $ 98,460   $ 272,031
Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 9,112   39,948
Fair Value, Measurements, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Short term notes receivable     4,476
Assets measured at fair value 552,456   581,947
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Short term notes receivable     0
Assets measured at fair value 450,811   313,735
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Short term notes receivable     0
Assets measured at fair value 101,645   263,736
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Short term notes receivable   $ 4,900 4,476
Assets measured at fair value     4,476
Money market funds | Fair Value, Measurements, Recurring | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 431,081   253,155
Money market funds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 431,081   253,155
Money market funds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 0   0
Money market funds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds     0
Commercial paper | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 17,793   58,502
Commercial paper | Fair Value, Measurements, Recurring | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 4,681   7,246
Commercial paper | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 17,793   58,502
Commercial paper | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 0   0
Commercial paper | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
Commercial paper | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 4,681   7,246
Commercial paper | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 17,793   58,502
Commercial paper | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds     0
Commercial paper | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
US Treasury and Government [Member] | Fair Value, Measurements, Recurring | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 2,195    
US Treasury and Government [Member] | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 2,195    
US Treasury and Government [Member] | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 0    
Corporate bonds | Fair Value, Measurements, Recurring | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 3,880   2,016
Corporate bonds | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 45,052   145,557
Corporate bonds | Fair Value, Measurements, Recurring | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 4,960   24,993
Corporate bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 0   0
Corporate bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
Corporate bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
Corporate bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds 3,880   2,016
Corporate bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 45,052   145,557
Corporate bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 4,960   24,993
Corporate bonds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Cash Equivalents      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Money market funds     0
Corporate bonds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
Corporate bonds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
Debt Security, Government, Non-US [Member] | Fair Value, Measurements, Recurring | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 1,407    
U.S. government agency bonds | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 19,904   3,006
U.S. government agency bonds | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 1,407   14,955
U.S. government agency bonds | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 19,904   3,006
U.S. government agency bonds | Fair Value, Measurements, Recurring | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     14,955
U.S. government agency bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
U.S. government agency bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
U.S. government agency bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 19,904   3,006
U.S. government agency bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 1,407   14,955
U.S. government agency bonds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
U.S. government agency bonds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
Israeli funds | Fair Value, Measurements, Recurring | Other assets      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets 3,047   3,075
Israeli funds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other assets      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets 0   0
Israeli funds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Other assets      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets 3,047   3,075
Israeli funds | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Other assets      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets     0
Municipal Securities | Fair Value, Measurements, Recurring | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 501    
Municipal Securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0    
Municipal Securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 501    
Asset-backed Securities | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 501    
Asset-backed Securities | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     60,580
Asset-backed Securities | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     60,580
Asset-backed Securities | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
Asset-backed Securities | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
Certificates of Deposit | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 420   4,386
Certificates of Deposit | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 420   4,386
Certificates of Deposit | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0   0
Certificates of Deposit | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 420   4,386
Certificates of Deposit | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments     0
U.S. Government Treasury Bonds | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 15,291   $ 60,580
U.S. Government Treasury Bonds | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 2,244    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 15,291    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 2,244    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 15,291    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 2,244    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Short-term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments 0    
U.S. Government Treasury Bonds | Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Long Term Investments      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Investments $ 0