v3.25.2
Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis and Categorized using Fair Value Hierarchy (Detail) - USD ($)
$ in Thousands
May 31, 2025
May 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities $ 24,323 $ 26,697
Total marketable equity securities 135,400 127,600
U.S. Treasury and other government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 24,200 26,559
Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 123 138
Fair Value, Measurements, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 24,323 26,697
Total marketable equity securities 135,419 127,626
Assets (liabilities) at fair value 142,490 152,094
Fair Value, Measurements, Recurring | U.S. Treasury and other government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 24,200 26,559
Fair Value, Measurements, Recurring | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 123 138
Fair Value, Measurements, Recurring | Stocks | Foreign    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 1,265 1,518
Fair Value, Measurements, Recurring | Stocks | Domestic    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 8,642 9,028
Fair Value, Measurements, Recurring | Mutual funds | Foreign    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 38,943 39,114
Fair Value, Measurements, Recurring | Mutual funds | Domestic    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 86,569 77,966
Fair Value, Measurements, Recurring | Contingent consideration liability    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Contingent consideration (17,252) (2,229)
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 9,907 10,546
Assets (liabilities) at fair value 9,907 10,546
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Stocks | Foreign    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 1,265 1,518
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Stocks | Domestic    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 8,642 9,028
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 24,323 26,697
Total marketable equity securities 125,512 117,080
Assets (liabilities) at fair value 149,835 143,777
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury and other government    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 24,200 26,559
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total available-for-sale securities 123 138
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Mutual funds | Foreign    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 38,943 39,114
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Mutual funds | Domestic    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total marketable equity securities 86,569 77,966
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets (liabilities) at fair value (17,252) (2,229)
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Contingent consideration liability    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Contingent consideration $ (17,252) $ (2,229)