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v3.19.3.a.u2

Employee Benefits - Plan Assets (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 3,007.0 | $ 2,690.8 | $ 2,966.8
Pension Plan | Level 1, 2, and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,778.1 | 1,626.2 |
Pension Plan | Level 1, 2, and 3 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 335.6 | 281.7 |
Pension Plan | Level 1, 2, and 3 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 322.3 | 280.4 |
Pension Plan | Level 1, 2, and 3 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 981.7 | 962.5 |
Pension Plan | Level 1, 2, and 3 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 138.5 | 101.6 |
Pension Plan | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 803.0 | 701.2 |
Pension Plan | Level 1 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 335.6 | 281.7 |
Pension Plan | Level 1 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 321.6 | 279.7 |
Pension Plan | Level 1 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 94.3 | 123.7 |
Pension Plan | Level 1 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 51.5 | 16.1 |
Pension Plan | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 975.1 | 925.0 |
Pension Plan | Level 2 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Pension Plan | Level 2 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.7 | 0.7 |
Pension Plan | Level 2 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 887.4 | 838.8 |
Pension Plan | Level 2 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 87.0 | 85.5 |
Pension Plan | Level 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Pension Plan | Level 3 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Pension Plan | Level 3 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 | 0.8
Pension Plan | Level 3 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Pension Plan | Level 3 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
Pension Plan | Investments measured at net asset value per share |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 1,228.9 | 1,064.6 |
OPEB Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 879.6 | 771.7 | 841.5
OPEB Plan | Level 1, 2, and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 528.6 | 467.0 |
OPEB Plan | Level 1, 2, and 3 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 103.0 | 88.2 |
OPEB Plan | Level 1, 2, and 3 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 107.5 | 92.4 |
OPEB Plan | Level 1, 2, and 3 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 285.0 | 270.4 |
OPEB Plan | Level 1, 2, and 3 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 33.1 | 16.0 |
OPEB Plan | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 354.0 | 307.1 |
OPEB Plan | Level 1 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 103.0 | 88.2 |
OPEB Plan | Level 1 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 107.3 | 92.2 |
OPEB Plan | Level 1 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 119.1 | 119.6 |
OPEB Plan | Level 1 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 24.6 | 7.1 |
OPEB Plan | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 174.6 | 159.9 |
OPEB Plan | Level 2 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
OPEB Plan | Level 2 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.2 | 0.2 |
OPEB Plan | Level 2 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 165.9 | 150.8 |
OPEB Plan | Level 2 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 8.5 | 8.9 |
OPEB Plan | Level 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
OPEB Plan | Level 3 | United States equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
OPEB Plan | Level 3 | International equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 | $ 0.2
OPEB Plan | Level 3 | United States bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
OPEB Plan | Level 3 | International bonds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | 0.0 | 0.0 |
OPEB Plan | Investments measured at net asset value per share |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair Value of Plan Assets | $ 351.0 | $ 304.7 |

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