Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Nov. 30, 2021 |
Nov. 30, 2020 |
Nov. 30, 2019 |
|
| Defined Benefit Plan Disclosure [Line Items] | |||
| Liabilities related to postretirement benefit plan | $ 76.3 | $ 77.7 | |
| Discounted rate for benefit plan | 2.30% | 1.80% | |
| 2022 | $ 2.6 | ||
| 2023 | 2.9 | ||
| 2024 | 3.2 | ||
| 2025 | 3.6 | ||
| 2026 | 4.4 | ||
| 2027-2031 | 23.0 | ||
| Supplemental Nonqualified Unfunded Retirement Plan | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Cash surrender value of insurance contracts | 40.5 | $ 43.5 | |
| Recognized investment gains on the cash surrender value of the Retirement Plan life insurance contracts | 1.1 | (0.7) | $ (2.1) |
| Benefits paid | 1.9 | 1.9 | 1.8 |
| Unfunded Death Benefit Plan | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Cash surrender value of insurance contracts | 18.5 | 18.8 | |
| Recognized investment gains on the cash surrender value of the Retirement Plan life insurance contracts | $ 0.3 | (0.3) | $ (0.9) |
| Benefits paid | $ 1.7 | ||