| Schedule of Net Benefit Costs of Assumptions Used |
Components of net periodic benefit costs for the three and nine months ended May 31, 2021 and 2020, are as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Three Months Ended May 31, | | Qualified
Pension Benefits | | Nonqualified
Pension Benefits | | Other Benefits | | | 2021 | | 2020 | | 2021 | | 2020 | | 2021 | | 2020 | | Components of net periodic benefit costs: | (Dollars in thousands) | | Service cost | $ | 11,307 | | | $ | 10,538 | | | $ | 108 | | | $ | 101 | | | $ | 297 | | | $ | 262 | | | Interest cost | 4,141 | | | 5,431 | | | 68 | | | 107 | | | 123 | | | 187 | | | Expected return on assets | (10,910) | | | (11,671) | | | — | | | — | | | — | | | — | | | Prior service cost (credit) amortization | 45 | | | 45 | | | (28) | | | (28) | | | (111) | | | (111) | | | Actuarial loss (gain) amortization | 5,447 | | | 5,396 | | | 53 | | | 25 | | | (341) | | | (348) | | |
| Net periodic benefit cost (benefit) | $ | 10,030 | | | $ | 9,739 | | | $ | 201 | | | $ | 205 | | | $ | (32) | | | $ | (10) | | | | | | | | | | | | | | | Nine Months Ended May 31, | | Qualified
Pension Benefits | | Nonqualified
Pension Benefits | | Other Benefits | | | 2021 | | 2020 | | 2021 | | 2020 | | 2021 | | 2020 | | Components of net periodic benefit costs: | (Dollars in thousands) | | Service cost | $ | 33,921 | | | $ | 31,613 | | | $ | 325 | | | $ | 304 | | | $ | 890 | | | $ | 787 | | | Interest cost | 12,422 | | | 16,292 | | | 205 | | | 322 | | | 369 | | | 560 | | | Expected return on assets | (32,731) | | | (35,013) | | | — | | | — | | | — | | | — | | | Prior service cost (credit) amortization | 134 | | | 134 | | | (85) | | | (85) | | | (334) | | | (334) | | | Actuarial loss (gain) amortization | 16,342 | | | 16,187 | | | 159 | | | 74 | | | (1,024) | | | (1,044) | | |
| Net periodic benefit cost (benefit) | $ | 30,088 | | | $ | 29,213 | | | $ | 604 | | | $ | 615 | | | $ | (99) | | | $ | (31) | |
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