XML 57 R41.htm IDEA: XBRL DOCUMENT v3.22.0.1
Fair Value Measurements - Fair Value Measurements of Cash Equivalents, Available-For-Sale Investment Securities and Equity Securities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure $ 499,785 $ 632,576
Money market fund    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 122,876 300,339
Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 266,701 531,736
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 122,876 300,339
Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 233,084 100,840
U.S. Treasury notes    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 140,187 230,088
U.S. Treasury notes | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 140,187 230,088
Equity securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 3,638 1,309
Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 3,638 1,309
Municipal Bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 25,984  
US Government Sponsored Enterprises Debt Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure 49,474 9,999
US Government Sponsored Enterprises Debt Securities | Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure   9,999
Corporate debt securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure   52,388
Corporate debt securities | Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure   52,388
Commercial paper    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure $ 157,626 38,453
Commercial paper | Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments, fair value disclosure   $ 38,453