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Commitments and Contingencies (Details) $ in Millions | 9 Months Ended
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Sep. 30, 2019 USD ($)
Other Commitments [Line Items] |
Purchase orders outstanding | $ 4.6
Purchase orders outstanding, term | 3 months
Performance Guarantee [Member] |
Other Commitments [Line Items] |
Bonds outstanding | $ 867.1
Estimated remaining costs for bonded projects | 378.7
Contingencies Excluding Wildfire and Health Insurance [Member] |
Other Commitments [Line Items] |
Insurance coverage deductible | 1.0
Wildfire [Member] |
Other Commitments [Line Items] |
Insurance coverage deductible | 2.0
Health Insurance [Member] |
Other Commitments [Line Items] |
Insurance coverage deductible | $ 0.2

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