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BENEFIT PLANS - Schedule of Assets by Fair Value (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | --- | ---
Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 3,666.2 | $ 4,118.2 | $ 4,124.7
Year End Allocation | 100.00% | 100.00% |
OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 1,775.9 | $ 1,673.3 | $ 1,549.3
Year End Allocation | 100.00% | 100.00% |
Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 791.0 | $ 809.4 |
Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,033.1 | 897.8 |
Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,788.9 | 2,252.1 |
Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 463.5 | 501.2 |
Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.1 |
Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,086.3 | 1,056.6 |
Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 279.3 | 274.3 |
Equities | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 1,265.9 | $ 1,222.0 |
Year End Allocation | 34.50% | 29.70% |
Equities | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 1,077.6 | $ 960.6 |
Year End Allocation | 60.60% | 57.40% |
Equities | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 793.3 | $ 801.1 |
Equities | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 948.2 | 829.0 |
Equities | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Equities | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Equities | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Equities | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Equities | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 472.6 | 420.9 |
Equities | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 129.4 | 131.6 |
Domestic | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 327.0 | $ 411.3 |
Year End Allocation | 8.90% | 10.00% |
Domestic | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 616.8 | $ 540.6 |
Year End Allocation | 34.70% | 32.30% |
Domestic | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 327.0 | $ 411.3 |
Domestic | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 616.8 | 540.6 |
Domestic | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Domestic | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Domestic | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Domestic | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Domestic | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Domestic | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 290.2 | $ 389.8 |
Year End Allocation | 7.90% | 9.50% |
International | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 267.2 | $ 288.4 |
Year End Allocation | 15.00% | 17.20% |
International | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 290.2 | $ 389.8 |
International | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 267.2 | 288.4 |
International | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trusts | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 648.7 | $ 420.9 |
Year End Allocation | 17.70% | 10.20% |
Common Collective Trusts | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 193.6 | $ 131.6 |
Year End Allocation | 10.90% | 7.90% |
Common Collective Trusts | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 176.1 | $ 0.0 |
Common Collective Trusts | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 64.2 | 0.0 |
Common Collective Trusts | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trusts | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trusts | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trusts | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trusts | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 472.6 | 420.9 |
Common Collective Trusts | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 129.4 | 131.6 |
Fixed Income | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 1,745.3 | $ 2,209.4 |
Year End Allocation | 47.60% | 53.60% |
Fixed Income | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 512.4 | $ 538.5 |
Year End Allocation | 28.90% | 32.20% |
Fixed Income | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ (2.3) | $ 8.3 |
Fixed Income | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 57.3 | 42.9 |
Fixed Income | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,747.6 | 2,201.1 |
Fixed Income | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 322.2 | 348.9 |
Fixed Income | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Fixed Income | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Fixed Income | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Fixed Income | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 132.9 | 146.7 |
Common Collective Trust - Debt | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 132.9 | $ 146.7 |
Year End Allocation | 7.50% | 8.80% |
Common Collective Trust - Debt | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Common Collective Trust - Debt | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trust - Debt | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Common Collective Trust - Debt | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 132.9 | 146.7 |
United States Government and Agency Securities | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 863.3 | $ 1,107.5 |
Year End Allocation | 23.60% | 26.90% |
United States Government and Agency Securities | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 157.1 | $ 164.7 |
Year End Allocation | 8.90% | 9.80% |
United States Government and Agency Securities | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ (2.3) | $ 8.3 |
United States Government and Agency Securities | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | (0.5) | 1.4 |
United States Government and Agency Securities | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 865.6 | 1,099.2 |
United States Government and Agency Securities | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 157.6 | 163.3 |
United States Government and Agency Securities | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
United States Government and Agency Securities | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
United States Government and Agency Securities | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
United States Government and Agency Securities | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Corporate Debt | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 719.2 | $ 894.8 |
Year End Allocation | 19.60% | 21.70% |
Corporate Debt | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 132.3 | $ 149.0 |
Year End Allocation | 7.50% | 8.90% |
Corporate Debt | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Corporate Debt | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Corporate Debt | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 719.2 | 894.8 |
Corporate Debt | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 132.3 | 149.0 |
Corporate Debt | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Corporate Debt | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Corporate Debt | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Corporate Debt | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Foreign Debt | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 136.1 | $ 167.1 |
Year End Allocation | 3.70% | 4.10% |
Foreign Debt | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 27.1 | $ 28.6 |
Year End Allocation | 1.50% | 1.70% |
Foreign Debt | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Foreign Debt | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Foreign Debt | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 136.1 | 167.1 |
Foreign Debt | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 27.1 | 28.6 |
Foreign Debt | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Foreign Debt | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Foreign Debt | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Foreign Debt | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
State and Local Government | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 25.8 | $ 38.7 |
Year End Allocation | 0.70% | 0.90% |
State and Local Government | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 62.8 | $ 49.3 |
Year End Allocation | 3.50% | 3.00% |
State and Local Government | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
State and Local Government | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 57.8 | 41.5 |
State and Local Government | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 25.8 | 38.7 |
State and Local Government | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 5.0 | 7.8 |
State and Local Government | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
State and Local Government | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
State and Local Government | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
State and Local Government | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other – Asset Backed | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.9 | $ 1.3 |
Year End Allocation | 0.00% | 0.00% |
Other – Asset Backed | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.2 | $ 0.2 |
Year End Allocation | 0.00% | 0.00% |
Other – Asset Backed | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Other – Asset Backed | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other – Asset Backed | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.9 | 1.3 |
Other – Asset Backed | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.2 | 0.2 |
Other – Asset Backed | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other – Asset Backed | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other – Asset Backed | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other – Asset Backed | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Infrastructure | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 112.9 | $ 101.4 |
Year End Allocation | 3.10% | 2.50% |
Infrastructure | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Infrastructure | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Infrastructure | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Infrastructure | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 112.9 | 101.4 |
Real Estate | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 227.9 | $ 239.3 |
Year End Allocation | 6.20% | 5.80% |
Real Estate | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Real Estate | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Real Estate | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Real Estate | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 227.9 | 239.3 |
Alternative Investments | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 223.8 | $ 241.8 |
Year End Allocation | 6.10% | 5.80% |
Alternative Investments | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Alternative Investments | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Alternative Investments | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Alternative Investments | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 223.8 | 241.8 |
Trusted Owned Life Insurance | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 141.3 | $ 152.3 |
Year End Allocation | 8.00% | 9.10% |
Trusted Owned Life Insurance | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Trusted Owned Life Insurance | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 141.3 | 152.3 |
Trusted Owned Life Insurance | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Trusted Owned Life Insurance | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International Equities | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 23.1 | $ 22.3 |
Year End Allocation | 1.30% | 1.30% |
International Equities | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
International Equities | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 23.1 | 22.3 |
International Equities | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
International Equities | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
United States Bonds | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 118.2 | $ 130.0 |
Year End Allocation | 6.70% | 7.80% |
United States Bonds | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
United States Bonds | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 118.2 | 130.0 |
United States Bonds | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
United States Bonds | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Cash and Cash Equivalents | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 68.5 | $ 84.8 |
Year End Allocation | 1.90% | 2.10% |
Cash and Cash Equivalents | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 30.7 | $ 28.8 |
Year End Allocation | 1.70% | 1.70% |
Cash and Cash Equivalents | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Cash and Cash Equivalents | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 27.6 | 25.9 |
Cash and Cash Equivalents | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 41.3 | 51.0 |
Cash and Cash Equivalents | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Cash and Cash Equivalents | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Cash and Cash Equivalents | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Cash and Cash Equivalents | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 27.2 | 33.8 |
Cash and Cash Equivalents | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 3.1 | 2.9 |
Other Pending Transactions and Accrued Income | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 21.9 | $ 19.5 |
Year End Allocation | 0.60% | 0.50% |
Other Pending Transactions and Accrued Income | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 13.9 | $ (6.9) |
Year End Allocation | 0.80% | (0.40%) |
Other Pending Transactions and Accrued Income | Level 1 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 0.0 | $ 0.0 |
Other Pending Transactions and Accrued Income | Level 1 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other Pending Transactions and Accrued Income | Level 2 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other Pending Transactions and Accrued Income | Level 2 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other Pending Transactions and Accrued Income | Level 3 | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.1 |
Other Pending Transactions and Accrued Income | Level 3 | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Other Pending Transactions and Accrued Income | Other | Pension Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 21.9 | 19.4 |
Other Pending Transactions and Accrued Income | Other | OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 13.9 | $ (6.9) |

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