Pension and Other Postretirement Benefits (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jan. 31, 2017 |
Jan. 31, 2016 |
Jan. 31, 2017 |
Jan. 31, 2016 |
|
| Pension Plan | ||||
| Defined Benefit Plans and Other Postretirement Benefit Plans | ||||
| Service cost | $ 446 | $ 267 | $ 913 | $ 756 |
| Interest cost | 474 | 484 | 931 | 967 |
| Expected return on plan assets | (411) | (485) | (887) | (962) |
| Amortization of Prior service costs | 0 | 2 | 1 | 4 |
| Amortization of Other actuarial loss | 485 | 209 | 914 | 496 |
| Net periodic benefit cost | 994 | 477 | 1,872 | 1,261 |
| Postretirement Health Plan | ||||
| Defined Benefit Plans and Other Postretirement Benefit Plans | ||||
| Service cost | 33 | 21 | 63 | 43 |
| Interest cost | 21 | 21 | 39 | 41 |
| Amortization of Prior service costs | (1) | (1) | (3) | (3) |
| Amortization of Other actuarial loss | 14 | 0 | 20 | 0 |
| Net periodic benefit cost | $ 67 | $ 41 | $ 119 | $ 81 |