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Commitments and Contingencies (Details) - USD ($) |  |  |  |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
May 24, 2018 | Jul. 21, 2017 | Jul. 03, 2017 | Apr. 01, 2017 | Sep. 30, 2017 | Dec. 31, 2014 | Sep. 30, 2018 | Sep. 02, 2016
URS | Design build contractor |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Damages claimed, value | $ 11,900,000 |  | $ 70,000,000 | $ 8,200,000 |  |  |  |
AECOM USA, Inc. | Minimum | New York Department of Environmental Conservation |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Damages claimed, value |  |  |  |  | $ 100,000 |  |  |
Advatech LLC |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Percentage of ownership in joint venture |  |  |  |  |  |  | 60.00% |
Advatech LLC | Genco |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Damages claimed, value |  | $ 81,000,000 |  |  |  |  |  |
Invoice amount |  |  |  |  |  |  |  | $ 81,000,000
DOE Deactivation, Demolition, And Removal Project | Department of Energy | Maximum |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Cost-reimbursement at risk |  |  |  |  |  |  | $ 106,000,000 |
DOE Deactivation, Demolition, And Removal Project | WGI Ohio and DOE | Minimum |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Cost-reimbursement at risk |  |  |  |  |  |  | 106,000,000 |
DOE Deactivation, Demolition, And Removal Project | WGI Ohio and DOE | Maximum |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Cost-reimbursement at risk |  |  |  |  |  |  | 146,000,000 |
DOE Deactivation, Demolition, And Removal Project | WGI Ohio |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Claim to DOE, including additional fees |  |  |  |  |  | $ 103,000,000 |  |
Possible costs which may exceed contracted amounts |  |  |  |  |  | $ 100,000,000 |  |
DOE Deactivation, Demolition, And Removal Project | WGI Ohio | Minimum |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Cost-reimbursement at risk |  |  |  |  |  |  | 146,000,000 |
AECOM-Canyon Equity Fund, L.P |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Capital commitments |  |  |  |  |  |  | $ 35,000,000 |
Term of capital commitments |  |  |  |  |  |  | 10 years |
Standby letter of credit |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Contingency liability |  |  |  |  |  |  | $ 515,100,000 |
Surety Bond |  |  |  |  |  |  |  |
Commitments and Contingencies |  |  |  |  |  |  |  |
Contingency liability |  |  |  |  |  |  | $ 5,300,000,000 |

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