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Risk Management Activities (Narrative) (Details) mMDth in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) mMDth	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Derivative [Line Items]
Limit of GCA Volumes	20.00%
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	$ 0.0	$ 0.0	$ 0.0
Minimum
Derivative [Line Items]
Commodity Contract Length	1 year
Maximum
Derivative [Line Items]
Commodity Contract Length	6 years
Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount	$ 500.0
Natural Gas
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | mMDth	124.5

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Nominal number of units used to calculate payment on derivative.

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