The value of the award the counter party seeks in the legal matter.

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Percentage of claim recoveries and costs due to purchaser.

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Percentage of claim recoveries and costs due to seller.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The minimum amount the entity agreed to spend under the long-term purchase commitment.

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No definition available.

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Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

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Amount of cost incurred on construction contract for unapproved change order, claim, or similar item subject to uncertainty.

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Commitments and Contingencies (Details) - USD ($) $ in Millions		1 Months Ended			6 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Mar. 31, 2022	Sep. 30, 2021	Dec. 06, 2019	Dec. 31, 2014
Commitments and Contingencies
Unsecured credit facilities					$ 432.3
New York
Commitments and Contingencies
Contingency liability					146.0
Percentage of claim recoveries due to seller	90.00%
Percentage of claim recoveries due to purchaser	10.00%
Montana
Commitments and Contingencies
Damages sought			$ 132.0	$ 79.0
Damages sought, counter party		$ 93.0
Department of Energy \| New York \| Minimum
Commitments and Contingencies
Contingency liability					106.0
Department of Energy \| New York \| Maximum
Commitments and Contingencies
Contingency liability					146.0
Fund investment capital commitments
Commitments and Contingencies
Commitment					$ 19.1
Commitment period					7 years
Standby letters of credit
Commitments and Contingencies
Outstanding standby letters of credit					$ 487.5	$ 478.5
Contingency liability					492.0
Surety Bond
Commitments and Contingencies
Contingency liability					3,400.0
Collectibility of Receivables
Commitments and Contingencies
Unapproved change orders								$ 103.0
Collectibility of Receivables \| New York
Commitments and Contingencies
Unapproved change orders							$ 60.4
Collectibility of Receivables \| New York \| Minimum
Commitments and Contingencies
Damages sought					148.5
Collectibility of Receivables \| New York \| Maximum
Commitments and Contingencies
Damages sought					329.4
Collectibility of Receivables \| Montana
Commitments and Contingencies
Unapproved change orders					90.0
Damages sought					$ 144.0