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v3.23.1

EMPLOYEE BENEFITS-COSTS AND CONTRIBUTIONS (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2023 | Mar. 31, 2022 | Dec. 31, 2022
Components of net periodic benefit cost (credit) |  |  |
Contributions and payments related to pension and OPEB plans | $ 5.5 | $ 3.6 |
Total regulatory assets | 3,325.3 |  | $ 3,306.9
Pension and OPEB costs |  |  |
Components of net periodic benefit cost (credit) |  |  |
Total regulatory assets | 701.9 |  | $ 714.3
Pension Benefits |  |  |
Components of net periodic benefit cost (credit) |  |  |
Service cost | 6.6 | 12.4 |
Interest cost | 30.8 | 22.8 |
Expected return on plan assets | (47.4) | (52.7) |
Amortization of prior service (credit) cost | 0.1 | 0.4 |
Amortization of net actuarial (gain) loss | 7.4 | 19.1 |
Net periodic benefit (credit) cost | (2.5) | 2.0 |
Contributions and payments related to pension and OPEB plans | 4.9 |  |
Estimated future employer contributions for the remainder of the year | 9.6 |  |
Pension Benefits | Pension and Other Postretirement Plans Cost |  |  |
Components of net periodic benefit cost (credit) |  |  |
Total regulatory assets | 2.1 |  |
Other Postretirement Benefits |  |  |
Components of net periodic benefit cost (credit) |  |  |
Service cost | 2.5 | 3.8 |
Interest cost | 5.4 | 3.9 |
Expected return on plan assets | (13.3) | (17.2) |
Amortization of prior service (credit) cost | (3.7) | (4.0) |
Amortization of net actuarial (gain) loss | (3.2) | (6.0) |
Net periodic benefit (credit) cost | (12.3) | $ (19.5) |
Contributions and payments related to pension and OPEB plans | 0.6 |  |
Estimated future employer contributions for the remainder of the year | 1.5 |  |
Other Postretirement Benefits | Pension and Other Postretirement Plans Cost |  |  |
Components of net periodic benefit cost (credit) |  |  |
Total regulatory assets | $ 3.7 |  |

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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
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