XML 76 R36.htm IDEA: XBRL DOCUMENT
v3.20.1

Defined Benefit Pension and Other Postretirement Plans (Tables) | 6 Months Ended
--- | ---
Mar. 31, 2020
Retirement Benefits [Abstract] |
Components of Net Periodic Pension Expense and Other Postretirement Benefit Costs | Net periodic pension cost and other postretirement benefit cost include the following components:
|  | Pension Benefits |  | Other Postretirement Benefits
Three Months Ended March 31, |  | 2020 |  | 2019 |  | 2020 |  | 2019
Service cost |  | $ | 2.8 |  |  | $ | 2.6 |  |  | $ | — |  |  | $ | 0.1 |
Interest cost |  | 5.8 |  |  | 6.8 |  |  | 0.1 |  |  | 0.2 |
Expected return on assets |  | (9.4 | ) |  | (9.1 | ) |  | (0.2 | ) |  | (0.2 | )
Curtailment gain |  | (1.1 | ) |  | — |  |  | — |  |  | — |
Amortization of: |  |  |  |  |  |  |  |
Prior service benefit |  | — |  |  | — |  |  | (0.1 | ) |  | (0.2 | )
Actuarial loss |  | 3.8 |  |  | 2.0 |  |  | 0.1 |  |  | — |
Net cost (benefit) |  | 1.9 |  |  | 2.3 |  |  | (0.1 | ) |  | (0.1 | )
Change in associated regulatory liabilities |  | — |  |  | — |  |  | (0.4 | ) |  | (0.4 | )
Net cost (benefit) after change in regulatory liabilities |  | $ | 1.9 |  |  | $ | 2.3 |  |  | $ | (0.5 | ) |  | $ | (0.5 | )
|  | Pension Benefits |  | Other Postretirement Benefits
Six Months Ended March 31, |  | 2020 |  | 2019 |  | 2020 |  | 2019
Service cost |  | $ | 5.6 |  |  | $ | 5.1 |  |  | $ | 0.1 |  |  | $ | 0.1 |
Interest cost |  | 11.6 |  |  | 13.6 |  |  | 0.3 |  |  | 0.4 |
Expected return on assets |  | (18.8 | ) |  | (18.1 | ) |  | (0.4 | ) |  | (0.4 | )
Curtailment gain |  | (1.1 | ) |  | — |  |  | — |  |  | — |
Amortization of: |  |  |  |  |  |  |  |
Prior service cost (benefit) |  | 0.1 |  |  | 0.1 |  |  | (0.2 | ) |  | (0.3 | )
Actuarial loss |  | 7.5 |  |  | 3.9 |  |  | 0.1 |  |  | — |
Net cost (benefit) |  | 4.9 |  |  | 4.6 |  |  | (0.1 | ) |  | (0.2 | )
Change in associated regulatory liabilities |  | — |  |  | — |  |  | (0.7 | ) |  | (0.7 | )
Net cost (benefit) after change in regulatory liabilities |  | $ | 4.9 |  |  | $ | 4.6 |  |  | $ | (0.8 | ) |  | $ | (0.9 | )

X
- References No definition available. + Details
Name: | us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration