The total amount of guaranteed energy savings.

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The amount of bonds, as of the end of the accounting period, issued by a second party, guaranteeing the fulfillment of the Company's obligations to a third party. In the event that the Company does not meet its obligations, the third party will recover its losses via the bond.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Number of plaintiffs that have filed claims pertaining to a loss contingency.

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Commitments and Contingencies - Narrative (Details)				48 Months Ended
Commitments and Contingencies - Narrative (Details)	Sep. 20, 2018 subclass	Mar. 20, 2018 collective_bargaining_arrangement	Jan. 26, 2018 plaintiff	Oct. 24, 2018	Oct. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)
Loss Contingencies [Line Items]
Letters of credit					$ 149,800,000
Surety bonds					$ 596,800,000
Subsidiary ownership interest percentage					33.00%
Number of collective bargaining arrangements \| collective_bargaining_arrangement		3
Minimum
Loss Contingencies [Line Items]
Subsidiary ownership interest percentage					20.00%
Estimate of reasonably possible loss					$ 0
Maximum
Loss Contingencies [Line Items]
Subsidiary ownership interest percentage					50.00%
Estimate of reasonably possible loss					$ 6,000,000
Castro
Loss Contingencies [Line Items]
Number of plaintiffs \| plaintiff			3
Occurrence period after compliant				4 years
Bucio
Loss Contingencies [Line Items]
Number of certified subclasses \| subclass	4
Energy Savings Contracts
Loss Contingencies [Line Items]
Guarantee obligation					174,800,000	$ 171,700,000
Performance Guarantee \| Joint Venture
Loss Contingencies [Line Items]
Total guarantee					41,000,000
Pending Litigation
Loss Contingencies [Line Items]
Loss contingency amount accrued for probable losses					6,500,000
Pending Litigation \| Castro
Loss Contingencies [Line Items]
Loss contingency amount accrued for probable losses					$ 5,400,000