| Schedule of Components of Net Periodic Cost |
The components of the net periodic cost for pension benefits, including the Company's Pension Equalization Plan, and OPEB costs (principally health care and life insurance) for employees and covered dependents were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pension | OPEB | | Three Months Ended | Six Months Ended | Three Months Ended | Six Months Ended | | March 31, | March 31, | March 31, | March 31, | | (Thousands) | 2026 | 2025 | 2026 | 2025 | 2026 | 2025 | 2026 | 2025 | | Service cost | $ | 1,244 | | $ | 1,380 | | $ | 2,489 | | $ | 2,761 | | $ | 272 | | $ | 273 | | $ | 544 | | $ | 546 | | | Interest cost | 3,963 | | 3,859 | | 7,927 | | 7,717 | | 2,698 | | 2,097 | | 5,396 | | 4,194 | | | Expected return on plan assets | (6,137) | | (5,925) | | (12,274) | | (11,850) | | (2,260) | | (2,347) | | (4,519) | | (4,693) | | | Recognized actuarial loss | 39 | | 300 | | 77 | | 601 | | 2,796 | | 1,793 | | 5,592 | | 3,586 | | | Prior service credit amortization | — | | — | | — | | — | | (3,270) | | (3,270) | | (6,540) | | (6,540) | | | | | | | | | | | | Net periodic benefit (credit) cost | $ | (891) | | $ | (386) | | $ | (1,781) | | $ | (771) | | $ | 236 | | $ | (1,454) | | $ | 473 | | $ | (2,907) | |
|