Fair Value Measurements - Hierarchy Levels (Details) - USD ($)
$ in Thousands
Oct. 31, 2020
Jul. 31, 2020
Recurring basis    
Cash and cash equivalents:    
Total assets $ 106 $ 106
Accrued expenses:    
Contingent consideration 0  
Other long-term liabilities:    
Total liabilities 20,119 21,156
Recurring basis | Money markets    
Cash and cash equivalents:    
Cash and cash equivalents 106 106
Recurring basis | Level 1    
Cash and cash equivalents:    
Total assets 106 106
Accrued expenses:    
Contingent consideration 0  
Other long-term liabilities:    
Total liabilities 0 0
Recurring basis | Level 1 | Money markets    
Cash and cash equivalents:    
Cash and cash equivalents 106 106
Recurring basis | Level 2    
Cash and cash equivalents:    
Total assets 0 0
Accrued expenses:    
Contingent consideration 0  
Other long-term liabilities:    
Total liabilities 20,119 21,156
Recurring basis | Level 2 | Money markets    
Cash and cash equivalents:    
Cash and cash equivalents 0 0
Recurring basis | Level 3    
Cash and cash equivalents:    
Total assets 0 0
Accrued expenses:    
Contingent consideration 0  
Other long-term liabilities:    
Total liabilities 0 0
Recurring basis | Level 3 | Money markets    
Cash and cash equivalents:    
Cash and cash equivalents 0 0
Interest Rate Swap    
Accrued expenses:    
Interest rate swap 5,465 5,462
Interest Rate Swap | Recurring basis    
Accrued expenses:    
Interest rate swap 5,465 5,462
Other long-term liabilities:    
Interest rate swap 14,654 15,694
Interest Rate Swap | Recurring basis | Level 1    
Accrued expenses:    
Interest rate swap 0 0
Other long-term liabilities:    
Interest rate swap 0 0
Interest Rate Swap | Recurring basis | Level 2    
Accrued expenses:    
Interest rate swap 5,465 5,462
Other long-term liabilities:    
Interest rate swap 14,654 15,694
Interest Rate Swap | Recurring basis | Level 3    
Accrued expenses:    
Interest rate swap 0 0
Other long-term liabilities:    
Interest rate swap $ 0 $ 0