| Consolidated Stockholders' Equity Statement [Table Text Block] | 
    
     
      
       |   | 
         | 
             | 
         | 
         | 
         | 
         | 
         | 
         | 
             | 
         | 
         | 
         Accumulated   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         Additional   | 
         | 
         | 
         | 
         | 
         | 
         | 
         Other   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
       Common Stock | 
         | 
         | 
         Paid-in   | 
         | 
         | 
       Retained | 
         | 
         | 
         Comprehensive   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
         Shares   | 
         | 
         | 
         Amount   | 
         | 
         | 
         Capital   | 
         | 
         | 
         Earnings   | 
         | 
         | 
         Income(Loss)   | 
         | 
         | 
         Total   | 
         | 
       
      
       |   Balances at June 30, 2019   | 
         | 
         | 
       37,934 | 
         | 
         | 
        $ | 
       379 | 
         | 
         | 
        $ | 
       316,797 | 
         | 
         | 
        $ | 
       931,934 | 
         | 
         | 
        $ | 
       (83,521 | 
       ) | 
         | 
       $ | 
       1,165,589 | 
         | 
       
      
       |   Cumulative effect adjustments due to adoption of new accounting standards and other   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (879 | 
       ) | 
         | 
         | 
         | 
         | 
         | 
         | 
       (879 | 
       ) | 
       
      
       |   Net earnings   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       14,398 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       14,398 | 
         | 
       
      
       |   Other comprehensive loss   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (8,106 | 
       ) | 
         | 
         | 
       (8,106 | 
       ) | 
       
      
       |   Common stock issued for exercise of options   | 
         | 
         | 
       94 | 
         | 
         | 
         | 
       1 | 
         | 
         | 
         | 
       7,854 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       7,855 | 
         | 
       
      
       |   Common stock issued for restricted stock awards   | 
         | 
         | 
       50 | 
         | 
         | 
         | 
       0 | 
         | 
         | 
         | 
       (0 | 
       ) | 
         | 
         | 
       (1,926 | 
       ) | 
         | 
         | 
         | 
         | 
         | 
         | 
       (1,926 | 
       ) | 
       
      
       |   Cash dividends   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (12,169 | 
       ) | 
         | 
         | 
         | 
         | 
         | 
         | 
       (12,169 | 
       ) | 
       
      
       |   Stock-based compensation expense   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       8,267 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       8,267 | 
         | 
       
      
       |   Common stock issued to employee stock purchase plan   | 
         | 
         | 
       6 | 
         | 
         | 
         | 
       0 | 
         | 
         | 
         | 
       1,096 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       1,096 | 
         | 
       
      
       |   Employee stock purchase plan expense   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       99 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       99 | 
         | 
       
      
       |   Balances at September 30, 2019   | 
         | 
         | 
       38,084 | 
         | 
         | 
        $ | 
       381 | 
         | 
         | 
        $ | 
       334,112 | 
         | 
         | 
        $ | 
       931,358 | 
         | 
         | 
        $ | 
       (91,627 | 
       ) | 
         | 
       $ | 
       1,174,224 | 
         | 
       
     
     
    
     
      
       |   | 
         | 
             | 
         | 
         | 
         | 
         | 
         | 
         | 
             | 
         | 
         | 
         Accumulated   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         Additional   | 
         | 
         | 
         | 
         | 
         | 
         | 
         Other   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
       Common Stock | 
         | 
         | 
         Paid-in   | 
         | 
         | 
       Retained | 
         | 
         | 
         Comprehensive   | 
         | 
         | 
         | 
         | 
         | 
       
      
       |   | 
         | 
         Shares   | 
         | 
         | 
         Amount   | 
         | 
         | 
         Capital   | 
         | 
         | 
         Earnings   | 
         | 
         | 
         Income(Loss)   | 
         | 
         | 
         Total   | 
         | 
       
      
       |   Balances at June 30, 2018   | 
         | 
         | 
       37,608 | 
         | 
         | 
       $ | 
       376 | 
         | 
         | 
       $ | 
       246,568 | 
         | 
         | 
       $ | 
       876,931 | 
         | 
         | 
       $ | 
       (44,814 | 
         )   | 
         | 
       $ | 
       1,079,061 | 
         | 
       
      
       |   Cumulative effect adjustments due to adoption of new accounting standards and other   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       25,276 | 
         | 
         | 
         | 
       (24,682 | 
         )   | 
         | 
         | 
       594 | 
         | 
       
      
       |   Net earnings   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       17,403 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       17,403 | 
         | 
       
      
       |   Other comprehensive loss   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (1,136 | 
         )   | 
         | 
         | 
       (1,136 | 
         )   | 
       
      
       |   Common stock issued for exercise of options   | 
         | 
         | 
       166 | 
         | 
         | 
         | 
       2 | 
         | 
         | 
         | 
       15,609 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       15,611 | 
         | 
       
      
       |   Common stock issued for restricted stock awards   | 
         | 
         | 
       24 | 
         | 
         | 
         | 
       0 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (2,405 | 
         )   | 
         | 
         | 
         | 
         | 
         | 
         | 
       (2,405 | 
         )   | 
       
      
       |   Cash dividends   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       (12,066 | 
         )   | 
         | 
         | 
         | 
         | 
         | 
         | 
       (12,066 | 
         )   | 
       
      
       |   Stock-based compensation expense   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       11,327 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       11,327 | 
         | 
       
      
       |   Common stock issued to employee stock purchase plan   | 
         | 
         | 
       5 | 
         | 
         | 
         | 
       0 | 
         | 
         | 
         | 
       842 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       842 | 
         | 
       
      
       |   Employee stock purchase plan expense   | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       238 | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
         | 
       238 | 
         | 
       
      
       |   Balances at September 30, 2018   | 
         | 
         | 
       37,803 | 
         | 
         | 
       $ | 
       378 | 
         | 
         | 
       $ | 
       274,584 | 
         | 
         | 
       $ | 
       905,139 | 
         | 
         | 
       $ | 
       (70,632 | 
         )   | 
         | 
       $ | 
       1,109,469 | 
         | 
       
     
     
   
 | 
| Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] | 
    
     
      
       |   | 
         | 
         Unrealized  Gains  (Losses) on  Derivative Instruments   | 
         | 
         | 
         Foreign  Currency  Translation  Adjustments   | 
         | 
         | 
         Total   | 
         | 
       
      
       |   Balance as of June 30, 2019   | 
         | 
       $ | 
       (9,537 | 
       ) | 
         | 
       $ | 
       (73,983 | 
         )   | 
         | 
       $ | 
       (83,521 | 
         )   | 
       
      
       |   Other comprehensive income (loss), net of tax before reclassifications   | 
         | 
         | 
       (504 | 
       ) | 
         | 
         | 
       (7,602 | 
         )   | 
         | 
         | 
       (8,106 | 
         )   | 
       
      
       |   Balance as of September 30, 2019(1)   | 
         | 
       $ | 
       (10,041 | 
       ) | 
         | 
       $ | 
       (81,585 | 
         )   | 
         | 
       $ | 
       (91,627 | 
         )   | 
       
     
     
    
     
      
       |   | 
         | 
         Unrealized  Gains  (Losses) on  Derivative Instruments   | 
         | 
         | 
         Foreign  Currency  Translation  Adjustments   | 
         | 
         | 
         Total   | 
         | 
       
      
       |   Balance as of June 30, 2018(2)   | 
         | 
       $ | 
       - | 
         | 
         | 
       $ | 
       (69,496 | 
         )   | 
         | 
       $ | 
       (69,496 | 
         )   | 
       
      
       |   Other comprehensive income (loss), net of tax before reclassifications   | 
         | 
         | 
       - | 
         | 
         | 
         | 
       (1,136 | 
         )   | 
         | 
         | 
       (1,136 | 
         )   | 
       
      
       |   Balance as of September 30, 2018   | 
         | 
       $ | 
       - | 
         | 
         | 
       $ | 
       (70,632 | 
         )   | 
         | 
       $ | 
       (70,632 | 
         )   | 
       
     
     
   
 |