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Fair Value Measurements (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
ASSETS: |  |
Cash equivalents | $ 54.2 | $ 23.3
Trust assets | 0.0 | 0.2
Surety bonds |  | 1.8
Derivative instruments | 15.1 | 19.7
TOTAL | 69.3 | 45.0
LIABILITIES: |  |
Contingent obligation | 0.0 | 0.0
Derivative instruments | 16.7 | 4.2
TOTAL | 16.7 | 4.2
Level 1 |  |
ASSETS: |  |
Cash equivalents | 54.2 | 23.3
Trust assets | 0.0 | 0.2
Surety bonds |  | 1.8
Derivative instruments | 0.0 | 0.0
TOTAL | 54.2 | 25.3
LIABILITIES: |  |
Contingent obligation | 0.0 | 0.0
Derivative instruments | 0.0 | 0.0
TOTAL | 0.0 | 0.0
Level 2 |  |
ASSETS: |  |
Cash equivalents | 0.0 | 0.0
Trust assets | 0.0 | 0.0
Surety bonds |  | 0.0
Derivative instruments | 12.1 | 9.1
TOTAL | 12.1 | 9.1
LIABILITIES: |  |
Contingent obligation | 0.0 | 0.0
Derivative instruments | 16.7 | 1.3
TOTAL | 16.7 | 1.3
Level 3 |  |
ASSETS: |  |
Cash equivalents | 0.0 | 0.0
Trust assets | 0.0 | 0.0
Surety bonds |  | 0.0
Derivative instruments | 3.0 | 10.6
TOTAL | 3.0 | 10.6
LIABILITIES: |  |
Contingent obligation | 0.0 | 0.0
Derivative instruments | 0.0 | 2.9
TOTAL | $ 0.0 | $ 2.9

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