Pension and Other Postretirement Benefits (Tables)
 9 Months Ended
Apr. 30, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]  
Schedule of Net Benefit Costs
The components of net periodic pension and postretirement health benefit costs were as follows:

Pension Benefits
 (in thousands)
 For the Three Months Ended April 30,For the Nine Months Ended April 30,
 2022202120222021
Interest cost$267 $292 $801 $875 
Expected return on plan assets(646)(722)(1,939)(2,166)
Amortization of:
  Other actuarial loss36 218 108 653 
Net periodic benefit cost$(343)$(212)$(1,030)$(638)
Postretirement Health Benefits
 (in thousands)
 For the Three Months Ended April 30,For the Nine Months Ended April 30,
 2022202120222021
Service cost$31 $35 $92 $104 
Interest cost15 13 44 38 
Amortization of:
  Other actuarial loss— 1 — 3 
  Prior service costs(2)(2)(5)(5)
Net periodic benefit cost$44 $47 $131 $140 
Schedule of Assumptions Used
Assumptions used in the previous calculations were as follows:
    
 Pension BenefitsPostretirement Health Benefits
 For the Three and Nine Months Ended April 30,
 2022202120222021
Discount rate for net periodic benefit cost2.57 %2.14 %2.10 %1.63 %
Rate of increase in compensation levels— %— %— %— %
Long-term expected rate of return on assets6.50 %6.50 %— %— %

The medical cost trend assumption for postretirement health benefits was 7.05%. The graded trend rate is expected to decrease to an ultimate rate of 4.50% in fiscal year 2038.